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2016년 8월 20일 토요일
2016년 8월 14일 일요일
OCJP - 1Z0-851(D-3) 공부하자!
Name : OCJP Study
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 41
Given:
1. public class Test {
2. public enum Dogs {collie, harrier, shepherd};
3. public static void main(String [] args) {
4. Dogs myDog = Dogs.shepherd;
5. switch (myDog) {
6. case collie:
7. System.out.print("collie ");
8. case default:
9. System.out.print("retriever ");
10. case harrier:
11. System.out.print("harrier ");
12. }
13. }
14. }
What is the result?
: 결과는 무엇인가?
A. harrier
B. shepherd
C. retriever
D. Compilation fails.
E. retriever harrier
F. An exception is thrown at runtime.
Answer: D
QUESTION 42
Given:
1. public class Breaker2 {
2. static String o = "";
3.
4. public static void main(String[] args) {
5. z: for (int x = 2; x < 7; x++) {
6. if (x == 3)
7. continue;
8. if (x == 5)
9. break z;
10. o = o + x;
11. }
12. System.out.println(o);
13. }
14. }
What is the result?
: 결과는 무엇인가?
A. 2
B. 24
C. 234
D. 246
E. 2346
F. Compilation fails.
Answer: B
QUESTION 43
Given:
1. public static void main(String[] args) {
2. String str = "null";
3. if (str == null) {
4. System.out.println("null");
5. } else (str.length() == 0) {
6. System.out.println("zero");
7. } else {
8. System.out.println("some");
9. }
10. }
What is the result?
: 결과는 무엇인가?
A. null
B. zero
C. some
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
QUESTION 44
Given:
1. import java.io.IOException;
2.
3. class A {
4.
5. public void process() {
6. System.out.print("A,");
7. }
8.
9. }
10.
11.
12. class B extends A {
13.
14. public void process() throws IOException {
15. super.process();
16. System.out.print("B,");
17. throw new IOException();
18. }
19.
20. public static void main(String[] args) {
21. try {
22. new B().process();
23. } catch (IOException e) {
24. System.out.println("Exception");
25. }
26. }
27. }
What is the result?
: 결과는 무엇인가?
A. Exception
B. A,B,Exception
C. Compilation fails because of an error in line 20.
D. Compilation fails because of an error in line 14.
E. A NullPointerException is thrown at runtime.
Answer: D
QUESTION 45
Given:
11. public void genNumbers() {
12. ArrayList numbers = new ArrayList();
13. for(int i = 0; i < 10; i++) {
14. int value = i * ((int) Math.random());
15. Integer intObj = new Integer(value);
16. numbers.add(intObj);
17. }
18. System.out.println(numbers);
19. }
Which line of code marks the earliest point that an object referenced by intObj becomes a candidate for garbage collection?
: intObj 가 참조 된 객체가 garbage collection의 후보가 되는 최초의 지점을 표시한 라인은 어느 것인가?
A. Line 16
B. Line 17
C. Line 18
D. Line 19
E. The object is NOT a candidate for garbage collection.
Answer: D
QUESTION 46
Given:
1. public class GC {
2. private Object o;
3. private void doSomethingElse(Object obj) { o = obj; }
4. public void doSomething() {
5. Object o = new Object();
6. doSomethingElse(o);
7. o = new Object();
8. doSomethingElse(null);
9. o = null;
10. }
11. }
When the doSomething method is called, after which line does the Object created in line 5 become available for garbage collection?
: doSomething 메서드가 호출 될 때, 후에 5라인에서 만든 객체가 가비지 컬렉션에 사용할 수있게 하는 라인은 어는 것인가?
A. Line 5
B. Line 6
C. Line 7
D. Line 8
E. Line 9
F. Line 10
Answer: D
QUESTION 47
Given:
1. public class Pass2 {
2. public void main(String[] args) {
3. int x = 6;
4. Pass2 p = new Pass2();
5. p.doStuff(x);
6. System.out.print(" main x = " + x);
7. }
8.
9. void doStuff(int x) {
10. System.out.print(" doStuff x = " + x++);
11. }
12. }
And the command-line invocations:
javac Pass2.java
java Pass2 5
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. doStuff x = 6 main x = 6
D. doStuff x = 6 main x = 7
E. doStuff x = 7 main x = 6
F. doStuff x = 7 main x = 7
Answer: B
QUESTION 48
Given:
1. interface DeclareStuff {
2. public static final int EASY = 3;
3.
4. void doStuff(int t);
5. }
6.
7. public class TestDeclare implements DeclareStuff {
8. public static void main(String[] args) {
9. int x = 5;
10. new TestDeclare().doStuff(++x);
11. }
12.
13. void doStuff(int s) {
14. s += EASY + ++s;
15. System.out.println("s " + s);
16. }
17. }
What is the result?
: 결과는 무엇인가?
A. s 14
B. s 16
C. s 10
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
QUESTION 49
A class games.cards.Poker is correctly defined in the jar file Poker.jar. A user wants to execute the main method of Poker on a UNIX system using the command:
java games.cards.Poker
What allows the user to do this?
: 유저가 이것을 할 수 있도록 한 것은 무엇인가?
A. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java
B. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java/*.jar
C. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java/Poker.jar
D. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java
E. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java/*.jar F. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java/Poker.jar
Answer: C
QUESTION 50
Given a correctly compiled class whose source code is:
1. package com.sun.sjcp;
2.
3. public class Commander {
4. public static void main(String[] args) {
5. // more code here
6. }
7. }
Assume that the class file is located in /foo/com/sun/sjcp/, the current directory is /foo/, and that the classpath contains "." (current directory). Which command line correctly runs Commander?
A. java Commander
B. java com.sun.sjcp.Commander
C. java com/sun/sjcp/Commander
D. java -cp com.sun.sjcp Commander
E. java -cp com/sun/sjcp Commander
Answer: B
QUESTION 51
Given:
interface DoStuff2 {
float getRange(int low, int high);
}
interface DoMore {
float getAvg(int a, int b, int c);
}
abstract class DoAbstract implements DoStuff2, DoMore {
}
06. class DoStuff implements DoStuff2 {
07. public float getRange(int x, int y) {
08. return 3.14f;
09. }
10. }
11.
12. interface DoAll extends DoMore {
13. float getAvg(int a, int b, int c, int d);
14. }
What is the result?
: 결과는 무엇인가?
A. The file will compile without error.
B. Compilation fails. Only line 7 contains an error.
C. Compilation fails. Only line 12 contains an error.
D. Compilation fails. Only line 13 contains an error.
E. Compilation fails. Only lines 7 and 12 contain errors.
F. Compilation fails. Only lines 7 and 13 contain errors.
G. Compilation fails. Lines 7, 12, and 13 contain errors.
Answer: A
QUESTION 52
Given:
public class Spock {
public static void main(String[] args) {
Long tail = 2000L;
Long distance = 1999L;
Long story = 1000L;
if ((tail > distance) ^ ((story * 2) == tail))
System.out.print("1");
if ((distance + 1 != tail) ^ ((story * 2) == distance))
System.out.print("2");
}
}
What is the result?
: 결과는 무엇인가?
A. 1
B. 2
C. 12
D. Compilation fails.
E. No output is produced.
F. An exception is thrown at runtime.
Answer: E
QUESTION 53
Given:
class Payload {
private int weight;
public Payload() {
}
public Payload(int w) {
weight = w;
}
public void setWeight(int w) {
weight = w;
}
public String toString() {
return Integer.toString(weight);
}
}
10. public class TestPayload {
11. static void changePayload(Payload p) {
12. /* insert code */
13. }
14.
15. public static void main(String[] args) {
16. Payload p = new Payload(200);
17. p.setWeight(1024);
18. changePayload(p);
19. System.out.println("p is " + p);
20. }
21. }
Which code fragment, inserted at the end of line 12, produces the output p is 420?
: 12라인의 끝에 삽입하여 출력 p가 420이 나오도록 하는 코드 조각은 어느 것인가?
A. p.setWeight(420);
B. p.changePayload(420);
C. p = new Payload(420);
D. Payload.setWeight(420);
E. p = Payload.setWeight(420);
Answer: A
QUESTION 54
Given:
class Line {
public class Point {
public int x, y;
}
public Point getPoint() {
return new Point();
}
}
class Triangle {
public Triangle() {
// insert code here
}
}
Which code, inserted at line 16, correctly retrieves a local instance of a Point object?
: 16라인에 삽입하여, Point 객체의 로컬 인스턴스를 올바르게 검색한 코드는 어느 것인가?
A. Point p = Line.getPoint();
B. Line.Point p = Line.getPoint();
C. Point p = (new Line()).getPoint();
D. Line.Point p = (new Line()).getPoint();
Answer: D
QUESTION 55
Given:
84. try {
85. ResourceConnection con = resourceFactory.getConnection();
86. Results r = con.query("GET INFO FROM CUSTOMER");
87. info = r.getData();
88. con.close();
89. } catch (ResourceException re) {
90. errorLog.write(re.getMessage());
91. }
92. return info;
Which statement is true if a ResourceException is thrown on line 86?
: ResourceException이 86라인에서 발생한다면 어느 문장이 사실인가?
A. Line 92 will not execute.
B. The connection will not be retrieved in line 85.
C. The resource connection will not be closed on line 88.
D. The enclosing method will throw an exception to its caller.
Answer: C
QUESTION 56
Given:
11. class X { public void foo() { System.out.print("X "); } }
12.
13. public class SubB extends X {
14. public void foo() throws RuntimeException {
15. super.foo();
16. if (true) throw new RuntimeException();
17. System.out.print("B ");
18. }
19. public static void main(String[] args) {
20. new SubB().foo();
21. }
22. }
What is the result?
: 결과는 무엇인가?
A. X, followed by an Exception.
B. No output, and an Exception is thrown.
C. Compilation fails due to an error on line 14.
D. Compilation fails due to an error on line 16.
E. Compilation fails due to an error on line 17.
F. X, followed by an Exception, followed by B.
Answer: A
QUESTION 57
Which two code fragments correctly create and initialize a static array of int elements? (Choose two.)
: 올바르게 만들고 int 요소의 정적 배열을 초기화한 두 코드 조각은? (2개를 고르시오.)
A. static final int[] a = { 100,200 };
B. static final int[] a; static { a=new int[2]; a[0]=100; a[1]=200; }
C. static final int[] a = new int[2]{ 100,200 };
D. static final int[] a; static void init() { a = new int[3]; a[0]=100; a[1]=200; }
Answer: AB
QUESTION 58
Given:
class Alpha {
public void foo() { System.out.print("Afoo "); }
}
public class Beta extends Alpha {
public void foo() { System.out.print("Bfoo "); }
public static void main(String[] args) {
Alpha a = new Beta();
Beta b = (Beta)a;
a.foo();
b.foo();
}
}
What is the result?
: 결과는 무엇인가?
A. Afoo Afoo
B. Afoo Bfoo
C. Bfoo Afoo
D. Bfoo Bfoo
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: D
QUESTION 59
Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object?
(Choose two.)
: StringBuilder 개체와 StringBuffer 개체를 바꿀 때 안전하지 않은 2가지 시나리오는?
A. When using versions of Java technology earlier than 5.0.
B. When sharing a StringBuffer among multiple threads.
C. When using the java.io class StringBufferInputStream.
D. When you plan to reuse the StringBuffer to build more than one string.
Answer: AB
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 41
Given:
1. public class Test {
2. public enum Dogs {collie, harrier, shepherd};
3. public static void main(String [] args) {
4. Dogs myDog = Dogs.shepherd;
5. switch (myDog) {
6. case collie:
7. System.out.print("collie ");
8. case default:
9. System.out.print("retriever ");
10. case harrier:
11. System.out.print("harrier ");
12. }
13. }
14. }
What is the result?
: 결과는 무엇인가?
A. harrier
B. shepherd
C. retriever
D. Compilation fails.
E. retriever harrier
F. An exception is thrown at runtime.
Answer: D
QUESTION 42
Given:
1. public class Breaker2 {
2. static String o = "";
3.
4. public static void main(String[] args) {
5. z: for (int x = 2; x < 7; x++) {
6. if (x == 3)
7. continue;
8. if (x == 5)
9. break z;
10. o = o + x;
11. }
12. System.out.println(o);
13. }
14. }
What is the result?
: 결과는 무엇인가?
A. 2
B. 24
C. 234
D. 246
E. 2346
F. Compilation fails.
Answer: B
QUESTION 43
Given:
1. public static void main(String[] args) {
2. String str = "null";
3. if (str == null) {
4. System.out.println("null");
5. } else (str.length() == 0) {
6. System.out.println("zero");
7. } else {
8. System.out.println("some");
9. }
10. }
What is the result?
: 결과는 무엇인가?
A. null
B. zero
C. some
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
QUESTION 44
Given:
1. import java.io.IOException;
2.
3. class A {
4.
5. public void process() {
6. System.out.print("A,");
7. }
8.
9. }
10.
11.
12. class B extends A {
13.
14. public void process() throws IOException {
15. super.process();
16. System.out.print("B,");
17. throw new IOException();
18. }
19.
20. public static void main(String[] args) {
21. try {
22. new B().process();
23. } catch (IOException e) {
24. System.out.println("Exception");
25. }
26. }
27. }
What is the result?
: 결과는 무엇인가?
A. Exception
B. A,B,Exception
C. Compilation fails because of an error in line 20.
D. Compilation fails because of an error in line 14.
E. A NullPointerException is thrown at runtime.
Answer: D
QUESTION 45
Given:
11. public void genNumbers() {
12. ArrayList numbers = new ArrayList();
13. for(int i = 0; i < 10; i++) {
14. int value = i * ((int) Math.random());
15. Integer intObj = new Integer(value);
16. numbers.add(intObj);
17. }
18. System.out.println(numbers);
19. }
Which line of code marks the earliest point that an object referenced by intObj becomes a candidate for garbage collection?
: intObj 가 참조 된 객체가 garbage collection의 후보가 되는 최초의 지점을 표시한 라인은 어느 것인가?
A. Line 16
B. Line 17
C. Line 18
D. Line 19
E. The object is NOT a candidate for garbage collection.
Answer: D
QUESTION 46
Given:
1. public class GC {
2. private Object o;
3. private void doSomethingElse(Object obj) { o = obj; }
4. public void doSomething() {
5. Object o = new Object();
6. doSomethingElse(o);
7. o = new Object();
8. doSomethingElse(null);
9. o = null;
10. }
11. }
When the doSomething method is called, after which line does the Object created in line 5 become available for garbage collection?
: doSomething 메서드가 호출 될 때, 후에 5라인에서 만든 객체가 가비지 컬렉션에 사용할 수있게 하는 라인은 어는 것인가?
A. Line 5
B. Line 6
C. Line 7
D. Line 8
E. Line 9
F. Line 10
Answer: D
QUESTION 47
Given:
1. public class Pass2 {
2. public void main(String[] args) {
3. int x = 6;
4. Pass2 p = new Pass2();
5. p.doStuff(x);
6. System.out.print(" main x = " + x);
7. }
8.
9. void doStuff(int x) {
10. System.out.print(" doStuff x = " + x++);
11. }
12. }
And the command-line invocations:
javac Pass2.java
java Pass2 5
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. doStuff x = 6 main x = 6
D. doStuff x = 6 main x = 7
E. doStuff x = 7 main x = 6
F. doStuff x = 7 main x = 7
Answer: B
QUESTION 48
Given:
1. interface DeclareStuff {
2. public static final int EASY = 3;
3.
4. void doStuff(int t);
5. }
6.
7. public class TestDeclare implements DeclareStuff {
8. public static void main(String[] args) {
9. int x = 5;
10. new TestDeclare().doStuff(++x);
11. }
12.
13. void doStuff(int s) {
14. s += EASY + ++s;
15. System.out.println("s " + s);
16. }
17. }
What is the result?
: 결과는 무엇인가?
A. s 14
B. s 16
C. s 10
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
QUESTION 49
A class games.cards.Poker is correctly defined in the jar file Poker.jar. A user wants to execute the main method of Poker on a UNIX system using the command:
java games.cards.Poker
What allows the user to do this?
: 유저가 이것을 할 수 있도록 한 것은 무엇인가?
A. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java
B. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java/*.jar
C. put Poker.jar in directory /stuff/java, and set the CLASSPATH to include /stuff/java/Poker.jar
D. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java
E. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java/*.jar F. put Poker.jar in directory /stuff/java/games/cards, and set the CLASSPATH to include /stuff/java/Poker.jar
Answer: C
QUESTION 50
Given a correctly compiled class whose source code is:
1. package com.sun.sjcp;
2.
3. public class Commander {
4. public static void main(String[] args) {
5. // more code here
6. }
7. }
Assume that the class file is located in /foo/com/sun/sjcp/, the current directory is /foo/, and that the classpath contains "." (current directory). Which command line correctly runs Commander?
A. java Commander
B. java com.sun.sjcp.Commander
C. java com/sun/sjcp/Commander
D. java -cp com.sun.sjcp Commander
E. java -cp com/sun/sjcp Commander
Answer: B
QUESTION 51
Given:
interface DoStuff2 {
float getRange(int low, int high);
}
interface DoMore {
float getAvg(int a, int b, int c);
}
abstract class DoAbstract implements DoStuff2, DoMore {
}
06. class DoStuff implements DoStuff2 {
07. public float getRange(int x, int y) {
08. return 3.14f;
09. }
10. }
11.
12. interface DoAll extends DoMore {
13. float getAvg(int a, int b, int c, int d);
14. }
What is the result?
: 결과는 무엇인가?
A. The file will compile without error.
B. Compilation fails. Only line 7 contains an error.
C. Compilation fails. Only line 12 contains an error.
D. Compilation fails. Only line 13 contains an error.
E. Compilation fails. Only lines 7 and 12 contain errors.
F. Compilation fails. Only lines 7 and 13 contain errors.
G. Compilation fails. Lines 7, 12, and 13 contain errors.
Answer: A
QUESTION 52
Given:
public class Spock {
public static void main(String[] args) {
Long tail = 2000L;
Long distance = 1999L;
Long story = 1000L;
if ((tail > distance) ^ ((story * 2) == tail))
System.out.print("1");
if ((distance + 1 != tail) ^ ((story * 2) == distance))
System.out.print("2");
}
}
What is the result?
: 결과는 무엇인가?
A. 1
B. 2
C. 12
D. Compilation fails.
E. No output is produced.
F. An exception is thrown at runtime.
Answer: E
QUESTION 53
Given:
class Payload {
private int weight;
public Payload() {
}
public Payload(int w) {
weight = w;
}
public void setWeight(int w) {
weight = w;
}
public String toString() {
return Integer.toString(weight);
}
}
10. public class TestPayload {
11. static void changePayload(Payload p) {
12. /* insert code */
13. }
14.
15. public static void main(String[] args) {
16. Payload p = new Payload(200);
17. p.setWeight(1024);
18. changePayload(p);
19. System.out.println("p is " + p);
20. }
21. }
Which code fragment, inserted at the end of line 12, produces the output p is 420?
: 12라인의 끝에 삽입하여 출력 p가 420이 나오도록 하는 코드 조각은 어느 것인가?
A. p.setWeight(420);
B. p.changePayload(420);
C. p = new Payload(420);
D. Payload.setWeight(420);
E. p = Payload.setWeight(420);
Answer: A
QUESTION 54
Given:
class Line {
public class Point {
public int x, y;
}
public Point getPoint() {
return new Point();
}
}
class Triangle {
public Triangle() {
// insert code here
}
}
Which code, inserted at line 16, correctly retrieves a local instance of a Point object?
: 16라인에 삽입하여, Point 객체의 로컬 인스턴스를 올바르게 검색한 코드는 어느 것인가?
A. Point p = Line.getPoint();
B. Line.Point p = Line.getPoint();
C. Point p = (new Line()).getPoint();
D. Line.Point p = (new Line()).getPoint();
Answer: D
QUESTION 55
Given:
84. try {
85. ResourceConnection con = resourceFactory.getConnection();
86. Results r = con.query("GET INFO FROM CUSTOMER");
87. info = r.getData();
88. con.close();
89. } catch (ResourceException re) {
90. errorLog.write(re.getMessage());
91. }
92. return info;
Which statement is true if a ResourceException is thrown on line 86?
: ResourceException이 86라인에서 발생한다면 어느 문장이 사실인가?
A. Line 92 will not execute.
B. The connection will not be retrieved in line 85.
C. The resource connection will not be closed on line 88.
D. The enclosing method will throw an exception to its caller.
Answer: C
QUESTION 56
Given:
11. class X { public void foo() { System.out.print("X "); } }
12.
13. public class SubB extends X {
14. public void foo() throws RuntimeException {
15. super.foo();
16. if (true) throw new RuntimeException();
17. System.out.print("B ");
18. }
19. public static void main(String[] args) {
20. new SubB().foo();
21. }
22. }
What is the result?
: 결과는 무엇인가?
A. X, followed by an Exception.
B. No output, and an Exception is thrown.
C. Compilation fails due to an error on line 14.
D. Compilation fails due to an error on line 16.
E. Compilation fails due to an error on line 17.
F. X, followed by an Exception, followed by B.
Answer: A
QUESTION 57
Which two code fragments correctly create and initialize a static array of int elements? (Choose two.)
: 올바르게 만들고 int 요소의 정적 배열을 초기화한 두 코드 조각은? (2개를 고르시오.)
A. static final int[] a = { 100,200 };
B. static final int[] a; static { a=new int[2]; a[0]=100; a[1]=200; }
C. static final int[] a = new int[2]{ 100,200 };
D. static final int[] a; static void init() { a = new int[3]; a[0]=100; a[1]=200; }
Answer: AB
QUESTION 58
Given:
class Alpha {
public void foo() { System.out.print("Afoo "); }
}
public class Beta extends Alpha {
public void foo() { System.out.print("Bfoo "); }
public static void main(String[] args) {
Alpha a = new Beta();
Beta b = (Beta)a;
a.foo();
b.foo();
}
}
What is the result?
: 결과는 무엇인가?
A. Afoo Afoo
B. Afoo Bfoo
C. Bfoo Afoo
D. Bfoo Bfoo
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: D
QUESTION 59
Which two scenarios are NOT safe to replace a StringBuffer object with a StringBuilder object?
(Choose two.)
: StringBuilder 개체와 StringBuffer 개체를 바꿀 때 안전하지 않은 2가지 시나리오는?
A. When using versions of Java technology earlier than 5.0.
B. When sharing a StringBuffer among multiple threads.
C. When using the java.io class StringBufferInputStream.
D. When you plan to reuse the StringBuffer to build more than one string.
Answer: AB
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
critic
n.명사 비평가, 평론가
unseen
aj.형용사 눈에 보이지 않는
thorny
aj.형용사 (문제 등이) 곤란한
likewise
av.부사 똑같이; 비슷하게
get there
(어떤 장소에) 도착하다
Today.
critic
n.명사 비평가, 평론가
unseen
aj.형용사 눈에 보이지 않는
thorny
aj.형용사 (문제 등이) 곤란한
likewise
av.부사 똑같이; 비슷하게
get there
(어떤 장소에) 도착하다
OCJP - 1Z0-851(D-2) 공부하자!
Name : OCJP Study
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 21
Given:
class Animal {
public String noise() {
return "peep";
}
}
class Dog extends Animal {
public String noise() {
return "bark";
}
}
class Cat extends Animal {
public String noise() {
return "meow";
}
}
...
30. Animal animal = new Dog();
31. Cat cat = (Cat)animal;
32. System.out.println(cat.noise());
What is the result?
: 결과는 무엇인가?
A. peep
B. bark
C. meow
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: E
QUESTION 22
Given:
abstract class A {
abstract void a1();
void a2() {
}
}
class B extends A {
void a1() {
}
void a2() {
}
}
class C extends B {
void c1() {
}
}
And:
A x = new B();
C y = new C();
A z = new C();
What are four valid examples of polymorphic method calls? (Choose four.)
: 다형성 메소드 호출의 유효한 예 4개는 무엇인가? (4개를 고르시오.)
A. x.a2();
B. z.a2();
C. z.c1();
D. z.a1();
E. y.c1();
F. x.a1();
Answer: ABDF
QUESTION 23
Given:
class Employee {
String name;
double baseSalary;
Employee(String name, double baseSalary) {
this.name = name;
this.baseSalary = baseSalary;
}
}
public class SalesPerson extends Employee {
double commission;
public SalesPerson(String name, double baseSalary, double commission) {
// insert code here Line 13
}
}
Which two code fragments, inserted independently at line 13, will compile? (Choose two.)
: 13라인에 독립적으로 삽입하여 컴파일되는 코드 조각 2개는? (2개를 고르시오.)
A. super(name, baseSalary);
B. this.commission = commission;
C. super(); this.commission = commission;
D. this.commission = commission; super();
E. super(name, baseSalary); this.commission = commission;
F. this.commission = commission; super(name, baseSalary);
G. super(name, baseSalary, commission);
Answer: AE
QUESTION 24
A team of programmers is involved in reviewing a proposed design for a new utility class. After some discussion, they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself.
What design issue has the team discovered?
: 어떤 디자인 문제점을 팀은 발견했는가?
A. Tight coupling
B. Low cohesion
C. High cohesion
D. Loose coupling
E. Weak encapsulation
F. Strong encapsulation
Answer: E
QUESTION 25
Given that:
Gadget has-a Sprocket and Gadget has-a Spring and Gadget is-a Widget and Widget has-a Sprocket Which two code fragments represent these relationships? (Choose two.)
A. class Widget {
Sprocket s;
}
class Gadget extends Widget {
Spring s;
}
B. class Widget {
}
class Gadget extends Widget {
Spring s1;
Sprocket s2;
}
C. class Widget {
Sprocket s1;
Spring s2;
}
class Gadget extends Widget {
}
D. class Gadget {
Spring s;
}
class Widget extends Gadget {
Sprocket s;
}
E. class Gadget {
}
class Widget extends Gadget {
Sprocket s1;
Spring s2;
}
F. class Gadget {
Spring s1;
Sprocket s2;
}
class Widget extends Gadget {
}
Answer: AC
QUESTION 26
Given:
class Pizza {
java.util.ArrayList toppings;
public final void addTopping(String topping) {
toppings.add(topping);
}
public void removeTopping(String topping) {
toppings.remove(topping);
}
}
public class PepperoniPizza extends Pizza {
public void addTopping(String topping) {
System.out.println("Cannot add Toppings");
}
public static void main(String[] args) {
Pizza pizza = new PepperoniPizza();
pizza.addTopping("Mushrooms");
pizza.removeTopping("Peperoni");
}
}
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. Cannot add Toppings
C. The code runs with no output.
D. A NullPointerException is thrown in Line 4.
Answer: A
QUESTION 27
Which three statements are true? (Choose three.)
: 사실인 세 문장은? (3개를 고르시오.)
A. A final method in class X can be abstract if and only if X is abstract.
B. A protected method in class X can be overridden by any subclass of X.
C. A private static method can be called only within other static methods in class X.
D. A non-static public final method in class X can be overridden in any subclass of X.
E. A public static method in class X can be called by a subclass of X without explicitly referencing the class X.
F. A method with the same signature as a private final method in class X can be implemented in a subclass of X.
G. A protected method in class X can be overridden by a subclass of X only if the subclass is in the same package as X.
Answer: BEF
QUESTION 28
Click the Exhibit button.
1. public class Car {
2. private int wheelCount;
3. private String vin;
4. public Car(String vin){
5. this.vin = vin;
6. this.wheelCount = 4;
7. }
8. public String drive(){
9. return "zoom-zoom";
10. }
11. public String getInfo() {
12. return "VIN: " + vin + " wheels: " + wheelCount;
13. }
14. }
And
1. public class MeGo extends Car {
2. public MeGo(String vin) {
3. this.wheelCount = 3;
4. }
5. }
What two must the programmer do to correct the compilation errors? (Choose two.)
: 프로그래머가 컴파일 오류를 수정하려면 어떤 두 개를 반드시 해야 하나? (2개를 고르시오.)
A. insert a call to this() in the Car constructor
B. insert a call to this() in the MeGo constructor
C. insert a call to super() in the MeGo constructor
D. insert a call to super(vin) in the MeGo constructor
E. change the wheelCount variable in Car to protected
F. change line 3 in the MeGo class to super.wheelCount = 3;
Answer: DE
QUESTION 29
Click the Exhibit button.
1. import java.util.*;
2. public class TestSet{
3. enum Example {ONE, TWO, THREE }
4. public static void main(String[] args) {
5. Collection coll = new ArrayList();
6. coll.add(Example.THREE);
7. coll.add(Example.THREE);
8. coll.add(Example.THREE);
9. coll.add(Example.TWO);
10. coll.add(Example.TWO);
11. coll.add(Example.ONE);
12. Set set = new HashSet(coll);
13. }
14. }
Which statement is true about the set variable on line 12?
: 12라인에 설정된 변수에 관련해서 사실인 문장은?
A. The set variable contains all six elements from the coll collection, and the order is guaranteed to be preserved.
B. The set variable contains only three elements from the coll collection, and the order is guaranteed to be preserved.
C. The set variable contains all six elements from the coll collection, but the order is NOT guaranteed to be preserved.
D. The set variable contains only three elements from the coll collection, but the order is NOT guaranteed to be preserved.
Answer: D
QUESTION 30
Given:
public class Person {
private String name, comment;
private int age;
public Person(String n, int a, String c) {
name = n;
age = a;
comment = c;
}
public boolean equals(Object o) {
if (!(o instanceof Person))
return false;
Person p = (Person) o;
return age == p.age && name.equals(p.name);
}
}
What is the appropriate definition of the hashCode method in class Person?
: Person 클래스의 hashCode 메소드의 적절한 정의는 무엇인가?
A. return super.hashCode();
B. return name.hashCode() + age * 7;
C. return name.hashCode() + comment.hashCode() / 2;
D. return name.hashCode() + comment.hashCode() / 2 - age * 3;
Answer: B
QUESTION 31
Given:
public class Key {
private long id1;
private long id2;
// class Key methods
}
A programmer is developing a class Key, that will be used as a key in a standard java.util.HashMap. Which two methods should be overridden to assure that Key works correctly as a key? (Choose two.)
A. public int hashCode()
B. public boolean equals(Key k)
C. public int compareTo(Object o)
D. public boolean equals(Object o)
E. public boolean compareTo(Key k)
Answer: AD
QUESTION 32
A programmer has an algorithm that requires a java.util.List that provides an efficient implementation of add(0, object), but does NOT need to support quick random access. What supports these requirements?
A. java.util.Queue
B. java.util.ArrayList
C. java.util.LinearList
D. java.util.LinkedList
Answer: D
QUESTION 33
Given a class whose instances, when found in a collection of objects, are sorted by using the compareTo() method, which two statements are true? (Choose two.)
A. The class implements java.lang.Comparable.
B. The class implements java.util.Comparator.
C. The interface used to implement sorting allows this class to define only one sort sequence.
D. The interface used to implement sorting allows this class to define many different sort sequences.
Answer: AC
QUESTION 34
Given:
1. import java.util.*;
2.
3. public class Explorer3 {
4. public static void main(String[] args) {
5. TreeSet<Integer> s = new TreeSet<Integer>();
6. TreeSet<Integer> subs = new TreeSet<Integer>();
7. for (int i = 606; i < 613; i++)
8. if (i % 2 == 0)
9. s.add(i);
10. subs = (TreeSet) s.subSet(608, true, 611, true);
11. subs.add(629);
12. System.out.println(s + " " + subs);
13. }
14. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. [608, 610, 612, 629] [608, 610]
D. [608, 610, 612, 629] [608, 610, 629]
E. [606, 608, 610, 612, 629] [608, 610]
F. [606, 608, 610, 612, 629] [608, 610, 629]
Answer: B
QUESTION 35
Given:
1. import java.util.*;
2.
3. public class LetterASort {
4. public static void main(String[] args) {
5. ArrayList<String> strings = new ArrayList<String>();
6. strings.add("aAaA");
7. strings.add("AaA");
8. strings.add("aAa");
9. strings.add("AAaa");
10. Collections.sort(strings);
11. for (String s : strings) {
12. System.out.print(s + " ");
13. }
14. }
15. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. aAaA aAa AAaa AaA
C. AAaa AaA aAa aAaA
D. AaA AAaa aAaA aAa
E. aAa AaA aAaA AAaa
F. An exception is thrown at runtime.
Answer: C
QUESTION 36
Given:
1. class A {
2. void foo() throws Exception {
3. throw new Exception();
4. }
5. }
6.
7. class SubB2 extends A {
8. void foo() {
9. System.out.println("B ");
10. }
11. }
12. class Tester {
13. public static void main(String[] args) {
14. A a = new SubB2();
15. a.foo();
16. }
17. }
What is the result?
: 결과는 무엇인가?
A. B B.
B, followed by an Exception.
C. Compilation fails due to an error on line 9.
D. Compilation fails due to an error on line 15.
E. An Exception is thrown with no other output
Answer: D
QUESTION 37
Given a method that must ensure that its parameter is not null:
11. public void someMethod(Object value) {
12. // check for null value
...
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null value?
: 12라인에 삽입하여, null 값을 적절하게 처리할 수 있는 방법은 무엇인가?
A. assert value == null;
B. assert value != null, "value is null";
C. if (value == null) { throw new AssertionException("value is null"); }
D. if (value == null) { throw new IllegalArgumentException("value is null"); }
Answer: D
QUESTION 38
Given:
1. public class Mule {
2. public static void main(String[] args) {
3. boolean assert = true;
4. if(assert) {
5. System.out.println("assert is true");
6. }
7. }
8. }
Which command-line invocations will compile?
: 명령 라인을 호출하여 컴파일 되는 것은 어느 것인가?
A. javac Mule.java
B. javac -source 1.3 Mule.java
C. javac -source 1.4 Mule.java
D. javac -source 1.5 Mule.java
Answer: B
QUESTION 39
Click the Exhibit button
1. public class A {
2. public void method1(){
3. B b = new B();
4. b.method2();
5. // more code here
6. }
7. }
1. public class B{
2. public void method2() {
3. C c = new C();
4. c.method3();
5. // more code here
6. }
7. }
1. public class C {
2. public void method3(){
3. // more code here
4. }
5. }
Given:
25. try {
26. A a = new A();
27. a.method1();
28. } catch (Exception e) {
29. System.out.print("an error occurred");
30. }
Which two statements are true if a NullPointerException is thrown on line 3 of class C? (Choose two.)
: NullPointerException 이 C 클래스의 3라인에서 발생한다면 사실인 2 문장은? (2개를 고르시오.)
A. The application will crash.
B. The code on line 29 will be executed.
C. The code on line 5 of class A will execute.
D. The code on line 5 of class B will execute.
E. The exception will be propagated back to line 27.
Answer: BE
QUESTION 40
Given:
1. public class Venus {
2. public static void main(String[] args) {
3. int[] x = { 1, 2, 3 };
4. int y[] = { 4, 5, 6 };
5. new Venus().go(x, y);
6. }
7.
8. void go(int[]... z) {
9. for (int[] a : z)
10. System.out.print(a[0]);
11. }
12. }
What is the result?
: 결과는 무엇인가?
A. 1
B. 12
C. 14
D. 123
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: C
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
incompetent
aj.형용사 무능한
athletic
aj.형용사 (몸이) 탄탄한
bristle
n.명사 짧고 뻣뻣한 털
probable
aj.형용사 (어떤 일이) 있을 것 같은, 개연성 있는
in full swing
한창 진행 중인[무르익은]
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 21
Given:
class Animal {
public String noise() {
return "peep";
}
}
class Dog extends Animal {
public String noise() {
return "bark";
}
}
class Cat extends Animal {
public String noise() {
return "meow";
}
}
...
30. Animal animal = new Dog();
31. Cat cat = (Cat)animal;
32. System.out.println(cat.noise());
What is the result?
: 결과는 무엇인가?
A. peep
B. bark
C. meow
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: E
QUESTION 22
Given:
abstract class A {
abstract void a1();
void a2() {
}
}
class B extends A {
void a1() {
}
void a2() {
}
}
class C extends B {
void c1() {
}
}
And:
A x = new B();
C y = new C();
A z = new C();
What are four valid examples of polymorphic method calls? (Choose four.)
: 다형성 메소드 호출의 유효한 예 4개는 무엇인가? (4개를 고르시오.)
A. x.a2();
B. z.a2();
C. z.c1();
D. z.a1();
E. y.c1();
F. x.a1();
Answer: ABDF
QUESTION 23
Given:
class Employee {
String name;
double baseSalary;
Employee(String name, double baseSalary) {
this.name = name;
this.baseSalary = baseSalary;
}
}
public class SalesPerson extends Employee {
double commission;
public SalesPerson(String name, double baseSalary, double commission) {
// insert code here Line 13
}
}
Which two code fragments, inserted independently at line 13, will compile? (Choose two.)
: 13라인에 독립적으로 삽입하여 컴파일되는 코드 조각 2개는? (2개를 고르시오.)
A. super(name, baseSalary);
B. this.commission = commission;
C. super(); this.commission = commission;
D. this.commission = commission; super();
E. super(name, baseSalary); this.commission = commission;
F. this.commission = commission; super(name, baseSalary);
G. super(name, baseSalary, commission);
Answer: AE
QUESTION 24
A team of programmers is involved in reviewing a proposed design for a new utility class. After some discussion, they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself.
What design issue has the team discovered?
: 어떤 디자인 문제점을 팀은 발견했는가?
A. Tight coupling
B. Low cohesion
C. High cohesion
D. Loose coupling
E. Weak encapsulation
F. Strong encapsulation
Answer: E
QUESTION 25
Given that:
Gadget has-a Sprocket and Gadget has-a Spring and Gadget is-a Widget and Widget has-a Sprocket Which two code fragments represent these relationships? (Choose two.)
A. class Widget {
Sprocket s;
}
class Gadget extends Widget {
Spring s;
}
B. class Widget {
}
class Gadget extends Widget {
Spring s1;
Sprocket s2;
}
C. class Widget {
Sprocket s1;
Spring s2;
}
class Gadget extends Widget {
}
D. class Gadget {
Spring s;
}
class Widget extends Gadget {
Sprocket s;
}
E. class Gadget {
}
class Widget extends Gadget {
Sprocket s1;
Spring s2;
}
F. class Gadget {
Spring s1;
Sprocket s2;
}
class Widget extends Gadget {
}
Answer: AC
QUESTION 26
Given:
class Pizza {
java.util.ArrayList toppings;
public final void addTopping(String topping) {
toppings.add(topping);
}
public void removeTopping(String topping) {
toppings.remove(topping);
}
}
public class PepperoniPizza extends Pizza {
public void addTopping(String topping) {
System.out.println("Cannot add Toppings");
}
public static void main(String[] args) {
Pizza pizza = new PepperoniPizza();
pizza.addTopping("Mushrooms");
pizza.removeTopping("Peperoni");
}
}
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. Cannot add Toppings
C. The code runs with no output.
D. A NullPointerException is thrown in Line 4.
Answer: A
QUESTION 27
Which three statements are true? (Choose three.)
: 사실인 세 문장은? (3개를 고르시오.)
A. A final method in class X can be abstract if and only if X is abstract.
B. A protected method in class X can be overridden by any subclass of X.
C. A private static method can be called only within other static methods in class X.
D. A non-static public final method in class X can be overridden in any subclass of X.
E. A public static method in class X can be called by a subclass of X without explicitly referencing the class X.
F. A method with the same signature as a private final method in class X can be implemented in a subclass of X.
G. A protected method in class X can be overridden by a subclass of X only if the subclass is in the same package as X.
Answer: BEF
QUESTION 28
Click the Exhibit button.
1. public class Car {
2. private int wheelCount;
3. private String vin;
4. public Car(String vin){
5. this.vin = vin;
6. this.wheelCount = 4;
7. }
8. public String drive(){
9. return "zoom-zoom";
10. }
11. public String getInfo() {
12. return "VIN: " + vin + " wheels: " + wheelCount;
13. }
14. }
And
1. public class MeGo extends Car {
2. public MeGo(String vin) {
3. this.wheelCount = 3;
4. }
5. }
What two must the programmer do to correct the compilation errors? (Choose two.)
: 프로그래머가 컴파일 오류를 수정하려면 어떤 두 개를 반드시 해야 하나? (2개를 고르시오.)
A. insert a call to this() in the Car constructor
B. insert a call to this() in the MeGo constructor
C. insert a call to super() in the MeGo constructor
D. insert a call to super(vin) in the MeGo constructor
E. change the wheelCount variable in Car to protected
F. change line 3 in the MeGo class to super.wheelCount = 3;
Answer: DE
QUESTION 29
Click the Exhibit button.
1. import java.util.*;
2. public class TestSet{
3. enum Example {ONE, TWO, THREE }
4. public static void main(String[] args) {
5. Collection coll = new ArrayList();
6. coll.add(Example.THREE);
7. coll.add(Example.THREE);
8. coll.add(Example.THREE);
9. coll.add(Example.TWO);
10. coll.add(Example.TWO);
11. coll.add(Example.ONE);
12. Set set = new HashSet(coll);
13. }
14. }
Which statement is true about the set variable on line 12?
: 12라인에 설정된 변수에 관련해서 사실인 문장은?
A. The set variable contains all six elements from the coll collection, and the order is guaranteed to be preserved.
B. The set variable contains only three elements from the coll collection, and the order is guaranteed to be preserved.
C. The set variable contains all six elements from the coll collection, but the order is NOT guaranteed to be preserved.
D. The set variable contains only three elements from the coll collection, but the order is NOT guaranteed to be preserved.
Answer: D
QUESTION 30
Given:
public class Person {
private String name, comment;
private int age;
public Person(String n, int a, String c) {
name = n;
age = a;
comment = c;
}
public boolean equals(Object o) {
if (!(o instanceof Person))
return false;
Person p = (Person) o;
return age == p.age && name.equals(p.name);
}
}
What is the appropriate definition of the hashCode method in class Person?
: Person 클래스의 hashCode 메소드의 적절한 정의는 무엇인가?
A. return super.hashCode();
B. return name.hashCode() + age * 7;
C. return name.hashCode() + comment.hashCode() / 2;
D. return name.hashCode() + comment.hashCode() / 2 - age * 3;
Answer: B
QUESTION 31
Given:
public class Key {
private long id1;
private long id2;
// class Key methods
}
A programmer is developing a class Key, that will be used as a key in a standard java.util.HashMap. Which two methods should be overridden to assure that Key works correctly as a key? (Choose two.)
A. public int hashCode()
B. public boolean equals(Key k)
C. public int compareTo(Object o)
D. public boolean equals(Object o)
E. public boolean compareTo(Key k)
Answer: AD
QUESTION 32
A programmer has an algorithm that requires a java.util.List that provides an efficient implementation of add(0, object), but does NOT need to support quick random access. What supports these requirements?
A. java.util.Queue
B. java.util.ArrayList
C. java.util.LinearList
D. java.util.LinkedList
Answer: D
QUESTION 33
Given a class whose instances, when found in a collection of objects, are sorted by using the compareTo() method, which two statements are true? (Choose two.)
A. The class implements java.lang.Comparable.
B. The class implements java.util.Comparator.
C. The interface used to implement sorting allows this class to define only one sort sequence.
D. The interface used to implement sorting allows this class to define many different sort sequences.
Answer: AC
QUESTION 34
Given:
1. import java.util.*;
2.
3. public class Explorer3 {
4. public static void main(String[] args) {
5. TreeSet<Integer> s = new TreeSet<Integer>();
6. TreeSet<Integer> subs = new TreeSet<Integer>();
7. for (int i = 606; i < 613; i++)
8. if (i % 2 == 0)
9. s.add(i);
10. subs = (TreeSet) s.subSet(608, true, 611, true);
11. subs.add(629);
12. System.out.println(s + " " + subs);
13. }
14. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. [608, 610, 612, 629] [608, 610]
D. [608, 610, 612, 629] [608, 610, 629]
E. [606, 608, 610, 612, 629] [608, 610]
F. [606, 608, 610, 612, 629] [608, 610, 629]
Answer: B
QUESTION 35
Given:
1. import java.util.*;
2.
3. public class LetterASort {
4. public static void main(String[] args) {
5. ArrayList<String> strings = new ArrayList<String>();
6. strings.add("aAaA");
7. strings.add("AaA");
8. strings.add("aAa");
9. strings.add("AAaa");
10. Collections.sort(strings);
11. for (String s : strings) {
12. System.out.print(s + " ");
13. }
14. }
15. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. aAaA aAa AAaa AaA
C. AAaa AaA aAa aAaA
D. AaA AAaa aAaA aAa
E. aAa AaA aAaA AAaa
F. An exception is thrown at runtime.
Answer: C
QUESTION 36
Given:
1. class A {
2. void foo() throws Exception {
3. throw new Exception();
4. }
5. }
6.
7. class SubB2 extends A {
8. void foo() {
9. System.out.println("B ");
10. }
11. }
12. class Tester {
13. public static void main(String[] args) {
14. A a = new SubB2();
15. a.foo();
16. }
17. }
What is the result?
: 결과는 무엇인가?
A. B B.
B, followed by an Exception.
C. Compilation fails due to an error on line 9.
D. Compilation fails due to an error on line 15.
E. An Exception is thrown with no other output
Answer: D
QUESTION 37
Given a method that must ensure that its parameter is not null:
11. public void someMethod(Object value) {
12. // check for null value
...
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null value?
: 12라인에 삽입하여, null 값을 적절하게 처리할 수 있는 방법은 무엇인가?
A. assert value == null;
B. assert value != null, "value is null";
C. if (value == null) { throw new AssertionException("value is null"); }
D. if (value == null) { throw new IllegalArgumentException("value is null"); }
Answer: D
QUESTION 38
Given:
1. public class Mule {
2. public static void main(String[] args) {
3. boolean assert = true;
4. if(assert) {
5. System.out.println("assert is true");
6. }
7. }
8. }
Which command-line invocations will compile?
: 명령 라인을 호출하여 컴파일 되는 것은 어느 것인가?
A. javac Mule.java
B. javac -source 1.3 Mule.java
C. javac -source 1.4 Mule.java
D. javac -source 1.5 Mule.java
Answer: B
QUESTION 39
Click the Exhibit button
1. public class A {
2. public void method1(){
3. B b = new B();
4. b.method2();
5. // more code here
6. }
7. }
1. public class B{
2. public void method2() {
3. C c = new C();
4. c.method3();
5. // more code here
6. }
7. }
1. public class C {
2. public void method3(){
3. // more code here
4. }
5. }
Given:
25. try {
26. A a = new A();
27. a.method1();
28. } catch (Exception e) {
29. System.out.print("an error occurred");
30. }
Which two statements are true if a NullPointerException is thrown on line 3 of class C? (Choose two.)
: NullPointerException 이 C 클래스의 3라인에서 발생한다면 사실인 2 문장은? (2개를 고르시오.)
A. The application will crash.
B. The code on line 29 will be executed.
C. The code on line 5 of class A will execute.
D. The code on line 5 of class B will execute.
E. The exception will be propagated back to line 27.
Answer: BE
QUESTION 40
Given:
1. public class Venus {
2. public static void main(String[] args) {
3. int[] x = { 1, 2, 3 };
4. int y[] = { 4, 5, 6 };
5. new Venus().go(x, y);
6. }
7.
8. void go(int[]... z) {
9. for (int[] a : z)
10. System.out.print(a[0]);
11. }
12. }
What is the result?
: 결과는 무엇인가?
A. 1
B. 12
C. 14
D. 123
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: C
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
incompetent
aj.형용사 무능한
athletic
aj.형용사 (몸이) 탄탄한
bristle
n.명사 짧고 뻣뻣한 털
probable
aj.형용사 (어떤 일이) 있을 것 같은, 개연성 있는
in full swing
한창 진행 중인[무르익은]
OCJP - 1Z0-851(D-1) 공부하자!
Name : OCJP Study
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 1
Given:
1. public class KungFu {
2. public static void main(String[] args) {
3. Integer x = 400;
4. Integer y = x;
5. x++;
6. StringBuilder sb1 = new StringBuilder("123");
7. StringBuilder sb2 = sb1;
8. sb1.append("5");
9. System.out.println((x == y) + " " + (sb1 == sb2));
10. }
11. }
What is the result?
: 결과는 무엇인가?
A. true true
B. false true
C. true false
D. false false
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: B
QUESTION 2
Given:
11. class Converter {
12. public static void main(String[] args) {
13. Integer i = args[0];
14. int j = 12;
15. System.out.println("It is " + (j == i) + " that j==i.");
16. }
17. }
What is the result when the programmer attempts to compile the code and run it with the command java Converter 12?
: 프로그래머가 코드를 컴파일하고 java Converter 로 12를 명형하여 실행하려고 한다면 결과는 무엇인가?
A. It is true that j==i.
B. It is false that j==i.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
QUESTION 3
Click the Exhibit button.
01. public class A {
02. public String doit(int x, int y){
03. return "a";
04. }
05.
06. public String doit(int... vals){
07. return "b";
08. }
09. }
Given:
25. A a = new A();
26. System.out.println(a.doit(4, 5));
What is the result?
: 결과는 무엇인가?
A. Line 26 prints a to System.out.
B. Line 26 prints b to System.out.
C. An exception is thrown at line 26 at runtime.
D. Compilation of class A will fail due to an error in line 6.
Answer: A
QUESTION 4
Given:
1. public class Plant {
2. private String name;
3.
4. public Plant(String name) {
5. this.name = name;
6. }
7.
8. public String getName() {
9. return name;
10. }
11. }
1. public class Tree extends Plant {
2. public void growFruit() {
3. }
4.
5. public void dropLeaves() {
6. }
7. }
Which statement is true?
: 사실인 문장은 어느 것인가?
A. The code will compile without changes.
B. The code will compile if public Tree() { Plant(); } is added to the Tree class.
C. The code will compile if public Plant() { Tree(); } is added to the Plant class.
D. The code will compile if public Plant() { this("fern"); } is added to the Plant class.
E. The code will compile if public Plant() { Plant("fern"); } is added to the Plant class.
Answer: D
QUESTION 5
Click the Exhibit button.
1. public class GoTest {
2. public static void main(String[] args) {
3. Sente a = new Sente(); a.go();
4. Goban b = new Goban(); b.go();
5. Stone c = new Stone(); c.go();
6. }
7. }
8.
9. class Sente implements Go {
10. public void go(){
11. System.out.println("go in Sente");
12. }
13. }
14.
15. class Goban extends Sente {
16. public void go(){
17. System.out.println("go in Goban");
18. }
19.
20. }
21. class Stone extends Goban implements Go{
22. }
23.
24. interface Go { public void go(); }
What is the result?
: 결과는 무엇인가?
A. go in Goban go in Sente go in Sente
B. go in Sente go in Sente go in Goban
C. go in Sente go in Goban go in Goban
D. go in Goban go in Goban go in Sente
E. Compilation fails because of an error in line 17.
Answer: C
QUESTION 6
Given:
11. public interface A111 {
12. String s = "yo";
13. public void method1();
14. }
15.
16.
17. interface B {}
18.
19.
20. interface C extends A111, B {
21. public void method1();
22. public void method1(int x);
23. }
What is the result?
: 결과는 무엇인가?
A. Compilation succeeds.
B. Compilation fails due to multiple errors.
C. Compilation fails due to an error only on line 20.
D. Compilation fails due to an error only on line 21.
E. Compilation fails due to an error only on line 22.
F. Compilation fails due to an error only on line 12.
Answer: A
QUESTION 7
Click the Exhibit button.
10. interface Foo{
11. int bar();
12. }
13.
14. public class Beta {
15.
16. class A implements Foo {
17. public int bar(){ return 1; }
18. }
19.
20. public int fubar(Foo foo){ return foo.bar(); }
21.
22. public void testFoo(){
23.
24. class A implements Foo{
25. public int bar(){return 2;}
26. }
27.
28. System.out.println(fubar(new A()));
29. }
30.
31. public static void main(String[] args) {
32. new Beta().testFoo();
33. }
34. }
Which three statements are true? (Choose three.)
: 사실인 3 문장은 어느 것인가? (3개를 고르시오.)
A. Compilation fails.
B. The code compiles and the output is 2.
C. If lines 16, 17 and 18 were removed, compilation would fail.
D. If lines 24, 25 and 26 were removed, compilation would fail.
E. If lines 16, 17 and 18 were removed, the code would compile and the output would be 2.
F. If lines 24, 25 and 26 were removed, the code would compile and the output would be 1.
Answer: BEF
QUESTION 8
Given:
1. public class TestOne {
2. public static void main (String[] args) throws Exception {
3. Thread.sleep(3000);
4. System.out.println("sleep");
5. }
6. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes normally and prints sleep.
D. The code executes normally, but nothing is printed.
Answer: C
QUESTION 9
Given:
1. public class Threads3 implements Runnable {
2. public void run() {
3. System.out.print("running");
4. }
5. public static void main(String[] args) {
6. Thread t = new Thread(new Threads3());
7. t.run();
8. t.run();
9. t.start();
10. }
11. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes and prints running.
D. The code executes and prints runningrunning.
E. The code executes and prints runningrunningrunning.
Answer: E
QUESTION 10
Given:
public class NamedCounter {
private final String name;
private int count;
public NamedCounter(String name) {
this.name = name;
}
public String getName() {
return name;
}
public void increment() {
count++;
}
public int getCount() {
return count;
}
public void reset() {
count = 0;
}
}
Which three changes should be made to adapt this class to be used safely by multiple threads? (Choose three.)
: 이 클래스를 멀티 스레드에 안전하게 사용하기 위해 적용해야 할 3가지 변화는 무엇인가? (3개를 고르시오.)
A. declare reset() using the synchronized keyword
B. declare getName() using the synchronized keyword
C. declare getCount() using the synchronized keyword
D. declare the constructor using the synchronized keyword
E. declare increment() using the synchronized keyword
Answer: ACE
QUESTION 11
Given that Triangle implements Runnable, and:
31. void go() throws Exception {
32. Thread t = new Thread(new Triangle());
33. t.start();
34. for(int x = 1; x < 100000; x++) {
35. //insert code here
36. if(x%100 == 0) System.out.print("g");
37. } }
38. public void run() {
39. try {
40. for(int x = 1; x < 100000; x++) {
41. // insert the same code here
42. if(x%100 == 0) System.out.print("t");
43. }
44. } catch (Exception e) {
45.
46. }
47. }
Which two statements, inserted independently at both lines 35 and 41, tend to allow both threads to temporarily pause and allow the other thread to execute? (Choose two.)
: 35, 41라인에 각가 독립적으로 삽입하여, 두 스레드를 일시적으로 중단하고 다른 스레드가 실행할 수 있도록 하는 2 문장은 어느 것인가?
A. Thread.wait();
B. Thread.join();
C. Thread.yield();
D. Thread.sleep(1);
E. Thread.notify();
Answer: CD
QUESTION 12
Given:
1. public class TestSeven extends Thread {
2. private static int x;
3. public synchronized void doThings() {
4. int current = x;
5. current++;
6. x = current;
7. }
8. public void run() {
9. doThings();
10. }
11. }
Which statement is true?
: 사실인 문장은?
A. Compilation fails.
B. An exception is thrown at runtime.
C. Synchronizing the run() method would make the class thread-safe.
D. The data in variable x are protected from concurrent access problems.
E. Declaring the doThings() method as static would make the class thread-safe.
F. Wrapping the statements within doThings() in a synchronized(new Object()) { } block would make the class thread-safe.
Answer: E
QUESTION 13
Given:
public class Yikes {
public static void go(Long n) {
System.out.print("Long ");
}
public static void go(Short n) {
System.out.print("Short ");
}
public static void go(int n) {
System.out.print("int ");
}
public static void main(String[] args) {
short y = 6;
long z = 7;
go(y);
go(z);
}
}
What is the result?
: 결과는 무엇인가?
A. int Long
B. Short Long
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: A
QUESTION 14
Given:
12. Date date = new Date();
13. df.setLocale(Locale.ITALY);
14. String s = df.format(date);
The variable df is an object of type DateFormat that has been initialized in line 11. What is the result if this code is run on December 14, 2000?
A. The value of s is 14-dic-2000.
B. The value of s is Dec 14, 2000.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
QUESTION 15
Given that c is a reference to a valid java.io.Console object, and:
11. String pw = c.readPassword("%s", "pw: ");
12. System.out.println("got " + pw);
13. String name = c.readLine("%s", "name: ");
14. System.out.println(" got ", name);
If the user types fido when prompted for a password, and then responds bob when prompted for a name, what is the result?
A. pw: got fido name: bob got bob
B. pw: fido got fido name: bob got bob
C. pw: got fido name: bob got bob
D. pw: fido got fido name: bob got bob
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: E
QUESTION 16
Given:
11. String test = "This is a test";
12. String[] tokens = test.split("\s");
13. System.out.println(tokens.length);
What is the result?
: 결과는 무엇인가?
A. 0
B. 1
C. 4
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
QUESTION 17
Given:
import java.io.*;
class Animal {
Animal() {
System.out.print("a");
}
}
class Dog extends Animal implements Serializable {
Dog() {
System.out.print("d");
}
}
public class Beagle extends Dog {
}
If an instance of class Beagle is created, then Serialized, then deSerialized, what is the result?
: Beagle 클래스의 인스턴스를 만든다면, 다음 역 직렬화 한 다음 직렬화 된 결과는 무엇인가?
A. ad
B. ada
C. add
D. adad
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: B
QUESTION 18
A team of programmers is involved in reviewing a proposed design for a new utility class. After some discussion, they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself. What design issue has the team discovered?
A. Tight coupling
B. Low cohesion
C. High cohesion
D. Loose coupling
E. Weak encapsulation
F. Strong encapsulation
Answer: E
QUESTION 19
Given a method that must ensure that its parameter is not null:
11. public void someMethod(Object value) {
12. // check for null value
...
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null value?
: 12라인에 삽입하여 null 값을 처리 할 수 있는 적절한 방법은 무엇인가?
A. assert value == null;
B. assert value != null, "value is null";
C. if (value == null) { throw new AssertionException("value is null"); }
D. if (value == null) { throw new IllegalArgumentException("value is null"); }
Answer: D
QUESTION 20
Given:
1. public class Target {
2. private int i = 0;
3. public int addOne() {
4. return ++i;
5. }
6. }
And:
1. public class Client {
2. public static void main(String[] args){
3. System.out.println(new Target().addOne());
4. }
5. }
Which change can you make to Target without affecting Client?
: Client 에 영향을 주지 않고 Target을 만들 수 있는 변화는 무엇인가?
A. Line 4 of class Target can be changed to return i++;
B. Line 2 of class Target can be changed to private int i = 1;
C. Line 3 of class Target can be changed to private int addOne(){
D. Line 2 of class Target can be changed to private Integer i = 0;
Answer: D
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
assent
n.명사 찬성, 승인
scholarship
n.명사 장학금
extraction
n.명사 (어떤 과정을 거쳐) 뽑아냄, 추출
madonna
n.명사 성모 마리아
something like
다소 …을 닮은, 약간 …비슷한[하게]
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 1
Given:
1. public class KungFu {
2. public static void main(String[] args) {
3. Integer x = 400;
4. Integer y = x;
5. x++;
6. StringBuilder sb1 = new StringBuilder("123");
7. StringBuilder sb2 = sb1;
8. sb1.append("5");
9. System.out.println((x == y) + " " + (sb1 == sb2));
10. }
11. }
What is the result?
: 결과는 무엇인가?
A. true true
B. false true
C. true false
D. false false
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: B
QUESTION 2
Given:
11. class Converter {
12. public static void main(String[] args) {
13. Integer i = args[0];
14. int j = 12;
15. System.out.println("It is " + (j == i) + " that j==i.");
16. }
17. }
What is the result when the programmer attempts to compile the code and run it with the command java Converter 12?
: 프로그래머가 코드를 컴파일하고 java Converter 로 12를 명형하여 실행하려고 한다면 결과는 무엇인가?
A. It is true that j==i.
B. It is false that j==i.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
QUESTION 3
Click the Exhibit button.
01. public class A {
02. public String doit(int x, int y){
03. return "a";
04. }
05.
06. public String doit(int... vals){
07. return "b";
08. }
09. }
Given:
25. A a = new A();
26. System.out.println(a.doit(4, 5));
What is the result?
: 결과는 무엇인가?
A. Line 26 prints a to System.out.
B. Line 26 prints b to System.out.
C. An exception is thrown at line 26 at runtime.
D. Compilation of class A will fail due to an error in line 6.
Answer: A
QUESTION 4
Given:
1. public class Plant {
2. private String name;
3.
4. public Plant(String name) {
5. this.name = name;
6. }
7.
8. public String getName() {
9. return name;
10. }
11. }
1. public class Tree extends Plant {
2. public void growFruit() {
3. }
4.
5. public void dropLeaves() {
6. }
7. }
Which statement is true?
: 사실인 문장은 어느 것인가?
A. The code will compile without changes.
B. The code will compile if public Tree() { Plant(); } is added to the Tree class.
C. The code will compile if public Plant() { Tree(); } is added to the Plant class.
D. The code will compile if public Plant() { this("fern"); } is added to the Plant class.
E. The code will compile if public Plant() { Plant("fern"); } is added to the Plant class.
Answer: D
QUESTION 5
Click the Exhibit button.
1. public class GoTest {
2. public static void main(String[] args) {
3. Sente a = new Sente(); a.go();
4. Goban b = new Goban(); b.go();
5. Stone c = new Stone(); c.go();
6. }
7. }
8.
9. class Sente implements Go {
10. public void go(){
11. System.out.println("go in Sente");
12. }
13. }
14.
15. class Goban extends Sente {
16. public void go(){
17. System.out.println("go in Goban");
18. }
19.
20. }
21. class Stone extends Goban implements Go{
22. }
23.
24. interface Go { public void go(); }
What is the result?
: 결과는 무엇인가?
A. go in Goban go in Sente go in Sente
B. go in Sente go in Sente go in Goban
C. go in Sente go in Goban go in Goban
D. go in Goban go in Goban go in Sente
E. Compilation fails because of an error in line 17.
Answer: C
QUESTION 6
Given:
11. public interface A111 {
12. String s = "yo";
13. public void method1();
14. }
15.
16.
17. interface B {}
18.
19.
20. interface C extends A111, B {
21. public void method1();
22. public void method1(int x);
23. }
What is the result?
: 결과는 무엇인가?
A. Compilation succeeds.
B. Compilation fails due to multiple errors.
C. Compilation fails due to an error only on line 20.
D. Compilation fails due to an error only on line 21.
E. Compilation fails due to an error only on line 22.
F. Compilation fails due to an error only on line 12.
Answer: A
QUESTION 7
Click the Exhibit button.
10. interface Foo{
11. int bar();
12. }
13.
14. public class Beta {
15.
16. class A implements Foo {
17. public int bar(){ return 1; }
18. }
19.
20. public int fubar(Foo foo){ return foo.bar(); }
21.
22. public void testFoo(){
23.
24. class A implements Foo{
25. public int bar(){return 2;}
26. }
27.
28. System.out.println(fubar(new A()));
29. }
30.
31. public static void main(String[] args) {
32. new Beta().testFoo();
33. }
34. }
Which three statements are true? (Choose three.)
: 사실인 3 문장은 어느 것인가? (3개를 고르시오.)
A. Compilation fails.
B. The code compiles and the output is 2.
C. If lines 16, 17 and 18 were removed, compilation would fail.
D. If lines 24, 25 and 26 were removed, compilation would fail.
E. If lines 16, 17 and 18 were removed, the code would compile and the output would be 2.
F. If lines 24, 25 and 26 were removed, the code would compile and the output would be 1.
Answer: BEF
QUESTION 8
Given:
1. public class TestOne {
2. public static void main (String[] args) throws Exception {
3. Thread.sleep(3000);
4. System.out.println("sleep");
5. }
6. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes normally and prints sleep.
D. The code executes normally, but nothing is printed.
Answer: C
QUESTION 9
Given:
1. public class Threads3 implements Runnable {
2. public void run() {
3. System.out.print("running");
4. }
5. public static void main(String[] args) {
6. Thread t = new Thread(new Threads3());
7. t.run();
8. t.run();
9. t.start();
10. }
11. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The code executes and prints running.
D. The code executes and prints runningrunning.
E. The code executes and prints runningrunningrunning.
Answer: E
QUESTION 10
Given:
public class NamedCounter {
private final String name;
private int count;
public NamedCounter(String name) {
this.name = name;
}
public String getName() {
return name;
}
public void increment() {
count++;
}
public int getCount() {
return count;
}
public void reset() {
count = 0;
}
}
Which three changes should be made to adapt this class to be used safely by multiple threads? (Choose three.)
: 이 클래스를 멀티 스레드에 안전하게 사용하기 위해 적용해야 할 3가지 변화는 무엇인가? (3개를 고르시오.)
A. declare reset() using the synchronized keyword
B. declare getName() using the synchronized keyword
C. declare getCount() using the synchronized keyword
D. declare the constructor using the synchronized keyword
E. declare increment() using the synchronized keyword
Answer: ACE
QUESTION 11
Given that Triangle implements Runnable, and:
31. void go() throws Exception {
32. Thread t = new Thread(new Triangle());
33. t.start();
34. for(int x = 1; x < 100000; x++) {
35. //insert code here
36. if(x%100 == 0) System.out.print("g");
37. } }
38. public void run() {
39. try {
40. for(int x = 1; x < 100000; x++) {
41. // insert the same code here
42. if(x%100 == 0) System.out.print("t");
43. }
44. } catch (Exception e) {
45.
46. }
47. }
Which two statements, inserted independently at both lines 35 and 41, tend to allow both threads to temporarily pause and allow the other thread to execute? (Choose two.)
: 35, 41라인에 각가 독립적으로 삽입하여, 두 스레드를 일시적으로 중단하고 다른 스레드가 실행할 수 있도록 하는 2 문장은 어느 것인가?
A. Thread.wait();
B. Thread.join();
C. Thread.yield();
D. Thread.sleep(1);
E. Thread.notify();
Answer: CD
QUESTION 12
Given:
1. public class TestSeven extends Thread {
2. private static int x;
3. public synchronized void doThings() {
4. int current = x;
5. current++;
6. x = current;
7. }
8. public void run() {
9. doThings();
10. }
11. }
Which statement is true?
: 사실인 문장은?
A. Compilation fails.
B. An exception is thrown at runtime.
C. Synchronizing the run() method would make the class thread-safe.
D. The data in variable x are protected from concurrent access problems.
E. Declaring the doThings() method as static would make the class thread-safe.
F. Wrapping the statements within doThings() in a synchronized(new Object()) { } block would make the class thread-safe.
Answer: E
QUESTION 13
Given:
public class Yikes {
public static void go(Long n) {
System.out.print("Long ");
}
public static void go(Short n) {
System.out.print("Short ");
}
public static void go(int n) {
System.out.print("int ");
}
public static void main(String[] args) {
short y = 6;
long z = 7;
go(y);
go(z);
}
}
What is the result?
: 결과는 무엇인가?
A. int Long
B. Short Long
C. Compilation fails.
D. An exception is thrown at runtime.
Answer: A
QUESTION 14
Given:
12. Date date = new Date();
13. df.setLocale(Locale.ITALY);
14. String s = df.format(date);
The variable df is an object of type DateFormat that has been initialized in line 11. What is the result if this code is run on December 14, 2000?
A. The value of s is 14-dic-2000.
B. The value of s is Dec 14, 2000.
C. An exception is thrown at runtime.
D. Compilation fails because of an error in line 13.
Answer: D
QUESTION 15
Given that c is a reference to a valid java.io.Console object, and:
11. String pw = c.readPassword("%s", "pw: ");
12. System.out.println("got " + pw);
13. String name = c.readLine("%s", "name: ");
14. System.out.println(" got ", name);
If the user types fido when prompted for a password, and then responds bob when prompted for a name, what is the result?
A. pw: got fido name: bob got bob
B. pw: fido got fido name: bob got bob
C. pw: got fido name: bob got bob
D. pw: fido got fido name: bob got bob
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: E
QUESTION 16
Given:
11. String test = "This is a test";
12. String[] tokens = test.split("\s");
13. System.out.println(tokens.length);
What is the result?
: 결과는 무엇인가?
A. 0
B. 1
C. 4
D. Compilation fails.
E. An exception is thrown at runtime.
Answer: D
QUESTION 17
Given:
import java.io.*;
class Animal {
Animal() {
System.out.print("a");
}
}
class Dog extends Animal implements Serializable {
Dog() {
System.out.print("d");
}
}
public class Beagle extends Dog {
}
If an instance of class Beagle is created, then Serialized, then deSerialized, what is the result?
: Beagle 클래스의 인스턴스를 만든다면, 다음 역 직렬화 한 다음 직렬화 된 결과는 무엇인가?
A. ad
B. ada
C. add
D. adad
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: B
QUESTION 18
A team of programmers is involved in reviewing a proposed design for a new utility class. After some discussion, they realize that the current design allows other classes to access methods in the utility class that should be accessible only to methods within the utility class itself. What design issue has the team discovered?
A. Tight coupling
B. Low cohesion
C. High cohesion
D. Loose coupling
E. Weak encapsulation
F. Strong encapsulation
Answer: E
QUESTION 19
Given a method that must ensure that its parameter is not null:
11. public void someMethod(Object value) {
12. // check for null value
...
20. System.out.println(value.getClass());
21. }
What, inserted at line 12, is the appropriate way to handle a null value?
: 12라인에 삽입하여 null 값을 처리 할 수 있는 적절한 방법은 무엇인가?
A. assert value == null;
B. assert value != null, "value is null";
C. if (value == null) { throw new AssertionException("value is null"); }
D. if (value == null) { throw new IllegalArgumentException("value is null"); }
Answer: D
QUESTION 20
Given:
1. public class Target {
2. private int i = 0;
3. public int addOne() {
4. return ++i;
5. }
6. }
And:
1. public class Client {
2. public static void main(String[] args){
3. System.out.println(new Target().addOne());
4. }
5. }
Which change can you make to Target without affecting Client?
: Client 에 영향을 주지 않고 Target을 만들 수 있는 변화는 무엇인가?
A. Line 4 of class Target can be changed to return i++;
B. Line 2 of class Target can be changed to private int i = 1;
C. Line 3 of class Target can be changed to private int addOne(){
D. Line 2 of class Target can be changed to private Integer i = 0;
Answer: D
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
assent
n.명사 찬성, 승인
scholarship
n.명사 장학금
extraction
n.명사 (어떤 과정을 거쳐) 뽑아냄, 추출
madonna
n.명사 성모 마리아
something like
다소 …을 닮은, 약간 …비슷한[하게]
OCJP - 1Z0-851(C-3) 공부하자!
Name : OCJP Study
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 41
A developer is creating a class Book, that needs to access class Paper. The Paper class is deployed in a JAR named myLib.jar. Which three, taken independently, will allow the developer to use the Paper class while compiling the Book class? (Choose three.)
A. The JAR file is located at $JAVA_HOME/jre/classes/myLib.jar.
B. The JAR file is located at $JAVA_HOME/jre/lib/ext/myLib.jar..
C. The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes
/foo/myLib.jar/Paper.class.
D. The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes
/foo/myLib.jar.
E. The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - cp
/foo/myLib.jar/Paper Book.java.
F. The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac -d /foo/myLib.jar
Book.java
G. The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - classpath
/foo/myLib.jar Book.java
Answer: BDG
QUESTION 42
Click the Exhibit button.
class Foo {
private int x;
public Foo( int x ){ this.x = x;}
public void setX( int x ) { this.x = x; }
public int getX(){ return x;}
}
public class Gamma {
static Foo fooBar(Foo foo) {
foo = new Foo(100);
return foo;
}
public static void main(String[] args) {
Foo foo = new Foo( 300 );
System.out.println( foo.getX() + "-");
Foo fooFoo = fooBar(foo);
System.out.println(foo.getX() + "-");
System.out.println(fooFoo.getX() + "-");
foo = fooBar( fooFoo);
System.out.println( foo.getX() + "-");
System.out.println(fooFoo.getX());
}
}
What is the output of the program shown in the exhibit?
: 전시에 표시된 프로그램의 출력물은 무엇인가?
A. 300-100-100-100-100
B. 300-300-100-100-100
C. 300-300-300-100-100
D. 300-300-300-300-100
Answer: B
QUESTION 43
Given classes defined in two different files:
1. package packageA;
2. public class Message {
3. String getText() {
4. return "text";
5. }
6. }
And:
1. package packageB;
2.
3. public class XMLMessage extends packageA.Message {
4. String getText() {
5. return "<msg>text</msg>";
6. }
7.
8. public static void main(String[] args) {
9. System.out.println(new XMLMessage().getText());
10. }
11. }
What is the result of executing XMLMessage.main?
: XMLMessage.main 을 실행한 것은 결과는 무엇인가?
A. text
B. Compilation fails.
C. <msg>text</msg>
D. An exception is thrown at runtime.
Answer: C
QUESTION 44
Given:
interface Fish {
}
class Perch implements Fish {
}
class Walleye extends Perch {
}
class Bluegill {
}
public class Fisherman {
public static void main(String[] args) {
Fish f = new Walleye();
Walleye w = new Walleye();
Bluegill b = new Bluegill();
if (f instanceof Perch)
System.out.print("f-p ");
if (w instanceof Fish)
System.out.print("w-f ");
if (b instanceof Fish)
System.out.print("b-f ");
}
}
What is the result?
: 결과는 무엇인가?
A. w-f
B. f-p w-f
C. w-f b-f
D. f-p w-f b-f
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: B
QUESTION 45
Given:
1. package com.company.application;
2.
3. public class MainClass {
4. public static void main(String[] args) {
5. }
6. }
And MainClass exists in the /apps/com/company/application directory. Assume the CLASSPATH environment variable is set to "." (current directory). Which two java commands entered at the command line will run MainClass? (Choose two.)
A. java MainClass if run from the /apps directory
B. java com.company.application.MainClass if run from the /apps directory
C. java -classpath /apps com.company.application.MainClass if run from any directory
D. java -classpath . MainClass if run from the /apps/com/company/application directory
E. java -classpath /apps/com/company/application:. MainClass if run from the /apps directory
F. java com.company.application.MainClass if run from the /apps/com/company/application directory
Answer: BC
QUESTION 46
Given
class Foo {
static void alpha() {
/* more code here */
}
void beta() {
/* more code here */
}
}
Which two statements are true? (Choose two.)
: 사실인 문장 2개는? (2개를 고르시오.)
A. Foo.beta() is a valid invocation of beta().
B. Foo.alpha() is a valid invocation of alpha().
C. Method beta() can directly call method alpha().
D. Method alpha() can directly call method beta().
Answer: BC
QUESTION 47
Given:
1. public class TestSeven extends Thread {
2. private static int x;
3. public synchronized void doThings() {
4. int current = x;
5. current++;
6. x = current;
7. }
8. public void run() {
9. doThings();
10. }
11. }
Which statement is true?
: 사실인 문장은?
A. Compilation fails.
B. An exception is thrown at runtime.
C. Synchronizing the run() method would make the class thread-safe.
D. The data in variable x are protected from concurrent access problems.
E. Declaring the doThings() method as static would make the class thread-safe.
F. Wrapping the statements within doThings() in a synchronized(new Object()) { } block would make the class thread-safe.
Answer: E
QUESTION 48
Given that the current directory is empty, and that the user has read and write privileges to the current directory, and the following:
1. import java.io.*;
2. public class Maker {
3. public static void main(String[] args) {
4. File dir = new File("dir");
5. File f = new File(dir, "f");
6. }
7. }
Which statement is true?
: 사실인 문장은?
A. Compilation fails.
B. Nothing is added to the file system.
C. Only a new file is created on the file system.
D. Only a new directory is created on the file system.
E. Both a new file and a new directory are created on the file system.
Answer: B
QUESTION 49
Given:
NumberFormat nf = NumberFormat.getInstance();
nf.setMaximumFractionDigits(4);
nf.setMinimumFractionDigits(2);
String a = nf.format(3.1415926);
String b = nf.format(2);
Which two statements are true about the result if the default locale is Locale.US? (Choose two.)
: 디폴트 지역이 Locale.US 일 경우 결과에 대해서 사실인 2 문장은? (2개를 고르시오.)
A. The value of b is 2.
B. The value of a is 3.14.
C. The value of b is 2.00.
D. The value of a is 3.141.
E. The value of a is 3.1415.
F. The value of a is 3.1416.
G. The value of b is 2.0000.
Answer: CF
QUESTION 50
Which three statements concerning the use of the java.io.Serializable interface are true? (Choose three.)
: java.io.Serializable 인터페이스 사용의 사실에 관한 3가지 문장은? (3개를 고르시오.)
A. Objects from classes that use aggregation cannot be serialized.
B. An object serialized on one JVM can be successfully deserialized on a different JVM.
C. The values in fields with the volatile modifier will NOT survive serialization and deserialization.
D. The values in fields with the transient modifier will NOT survive serialization and deserialization.
E. It is legal to serialize an object of a type that has a supertype that does NOT implement java.io.Serializable.
Answer: BDE
QUESTION 51
Given:
12. String csv = "Sue,5,true,3";
13. Scanner scanner = new Scanner( csv );
14. scanner.useDelimiter(",");
15. int age = scanner.nextInt();
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. After line 15, the value of age is 5.
C. After line 15, the value of age is 3.
D. An exception is thrown at runtime.
Answer: D
QUESTION 52
Given that c is a reference to a valid java.io.Console object, which two code fragments read a line of text from the console? (Choose two.)
: c 를 java.io.Console 개체에 대한 유효한 참조라고 한다면, 콘솔에서 한 줄의 텍스트를 읽을 수 있는 두 개의 코드 조각은? (2개를 고르시오.)
A. String s = c.readLine();
B. char[] c = c.readLine();
C. String s = c.readConsole();
D. char[] c = c.readConsole();
E. String s = c.readLine("%s", "name ");
F. char[] c = c.readLine("%s", "name ");
Answer: AE
QUESTION 53
Given:
11. String test = "a1b2c3";
12. String[] tokens = test.split("\\d");
13. for(String s: tokens) System.out.print(s + " ");
What is the result?
: 결과는 무엇인가?
A. a b c
B. 1 2 3
C. a1b2c3
D. a1 b2 c3
E. Compilation fails.
F. The code runs with no output.
G. An exception is thrown at runtime.
Answer: A
QUESTION 54
Given:
33. Date d = new Date(0);
34. String ds = "December 15, 2004";
35. // insert code here
36. try {
37. d = df.parse(ds);
38. }
39. catch(ParseException e) {
40. System.out.println("Unable to parse " + ds);
41. }
42. // insert code here too
What creates the appropriate DateFormat object and adds a day to the Date object?
: 날짜 형식 객체를 만들고 날짜 객체에 요일을 더하는 적절한 것은 무엇인가?
A. 35. DateFormat df = DateFormat.getDateFormat();
42. d.setTime( (60 * 60 * 24) + d.getTime());
B. 35. DateFormat df = DateFormat.getDateInstance();
42. d.setTime( (1000 * 60 * 60 * 24) + d.getTime());
C. 35. DateFormat df = DateFormat.getDateFormat();
42. d.setLocalTime( (1000*60*60*24) + d.getLocalTime());
D. 35. DateFormat df = DateFormat.getDateInstance();
42. d.setLocalTime( (60 * 60 * 24) + d.getLocalTime());
Answer: B
QUESTION 55
Given:
import java.util.*;
public class Quest {
public static void main(String[] args) {
String[] colors = {"blue", "red", "green", "yellow", "orange"};
Arrays.sort(colors);
int s2 = Arrays.binarySearch(colors, "orange");
int s3 = Arrays.binarySearch(colors, "violet");
System.out.println(s2 + " " + s3);
}
}
What is the result?
: 결과는 무엇인가?
A. 2 -1
B. 2 -4
C. 2 -5
D. 3 -1
E. 3 -4
F. 3 -5
G. Compilation fails.
H. An exception is thrown at runtime.
Answer: C
QUESTION 56
Given:
static void test() {
try {
String x = null;
System.out.print(x.toString() + " ");
}
finally { System.out.print("finally "); }
}
public static void main(String[] args) {
try { test(); }
catch (Exception ex) { System.out.print("exception "); }
}
What is the result?
: 결과는 무엇인가?
A. null
B. finally
C. null finally
D. Compilation fails.
E. finally exception
Answer: E
QUESTION 57
Given:
public static Collection get() {
Collection sorted = new LinkedList();
sorted.add("B");
sorted.add("C");
sorted.add("A");
return sorted;
}
public static void main(String[] args) {
for (Object obj: get()) {
System.out.print(obj + ", ");
}
}
What is the result?
: 결과는 무엇인가?
A. A, B, C,
B. B, C, A,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: B
QUESTION 58
Given:
public static Iterator reverse(List list) {
Collections.reverse(list);
return list.iterator();
}
public static void main(String[] args) {
List list = new ArrayList();
list.add("1");
list.add("2");
list.add("3");
for (Object obj: reverse(list))
System.out.print(obj + ", ");
}
What is the result?
: 결과는 무엇인가?
A. 3, 2, 1,
B. 1, 2, 3,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: C
QUESTION 59
Given:
public class Base {
public static final String FOO = "foo";
public static void main(String[] args) {
Base b = new Base();
Sub s = new Sub();
System.out.print(Base.FOO);
System.out.print(Sub.FOO);
System.out.print(b.FOO);
System.out.print(s.FOO);
System.out.print(((Base) s).FOO);
}
}
class Sub extends Base {
public static final String FOO = "bar";
}
What is the result?
: 결과는 무엇인가?
A. foofoofoofoofoo
B. foobarfoobarbar
C. foobarfoofoofoo
D. foobarfoobarfoo
E. barbarbarbarbar
F. foofoofoobarbar
G. foofoofoobarfoo
Answer: D
QUESTION 60
Given:
1. public interface A { public void m1(); }
2.
3. class B implements A { }
4. class C implements A { public void m1() { } }
5. class D implements A { public void m1(int x) { } }
6. abstract class E implements A { }
7. abstract class F implements A { public void m1() { } }
8. abstract class G implements A { public void m1(int x) { } }
What is the result?
: 결과는 무엇인가?
A. Compilation succeeds.
B. Exactly one class does NOT compile.
C. Exactly two classes do NOT compile.
D. Exactly four classes do NOT compile.
E. Exactly three classes do NOT compile.
Answer: C
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
extensive
aj.형용사 아주 넓은, 대규모의
kidney
n.명사 신장, 콩팥
receiver
n.명사 수화기
presentation
n.명사 제출, 제시; 수여, 증정
then again
그렇지 않고 또, 또 한편으로는
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 41
A developer is creating a class Book, that needs to access class Paper. The Paper class is deployed in a JAR named myLib.jar. Which three, taken independently, will allow the developer to use the Paper class while compiling the Book class? (Choose three.)
A. The JAR file is located at $JAVA_HOME/jre/classes/myLib.jar.
B. The JAR file is located at $JAVA_HOME/jre/lib/ext/myLib.jar..
C. The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes
/foo/myLib.jar/Paper.class.
D. The JAR file is located at /foo/myLib.jar and a classpath environment variable is set that includes
/foo/myLib.jar.
E. The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - cp
/foo/myLib.jar/Paper Book.java.
F. The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac -d /foo/myLib.jar
Book.java
G. The JAR file is located at /foo/myLib.jar and the Book class is compiled using javac - classpath
/foo/myLib.jar Book.java
Answer: BDG
QUESTION 42
Click the Exhibit button.
class Foo {
private int x;
public Foo( int x ){ this.x = x;}
public void setX( int x ) { this.x = x; }
public int getX(){ return x;}
}
public class Gamma {
static Foo fooBar(Foo foo) {
foo = new Foo(100);
return foo;
}
public static void main(String[] args) {
Foo foo = new Foo( 300 );
System.out.println( foo.getX() + "-");
Foo fooFoo = fooBar(foo);
System.out.println(foo.getX() + "-");
System.out.println(fooFoo.getX() + "-");
foo = fooBar( fooFoo);
System.out.println( foo.getX() + "-");
System.out.println(fooFoo.getX());
}
}
What is the output of the program shown in the exhibit?
: 전시에 표시된 프로그램의 출력물은 무엇인가?
A. 300-100-100-100-100
B. 300-300-100-100-100
C. 300-300-300-100-100
D. 300-300-300-300-100
Answer: B
QUESTION 43
Given classes defined in two different files:
1. package packageA;
2. public class Message {
3. String getText() {
4. return "text";
5. }
6. }
And:
1. package packageB;
2.
3. public class XMLMessage extends packageA.Message {
4. String getText() {
5. return "<msg>text</msg>";
6. }
7.
8. public static void main(String[] args) {
9. System.out.println(new XMLMessage().getText());
10. }
11. }
What is the result of executing XMLMessage.main?
: XMLMessage.main 을 실행한 것은 결과는 무엇인가?
A. text
B. Compilation fails.
C. <msg>text</msg>
D. An exception is thrown at runtime.
Answer: C
QUESTION 44
Given:
interface Fish {
}
class Perch implements Fish {
}
class Walleye extends Perch {
}
class Bluegill {
}
public class Fisherman {
public static void main(String[] args) {
Fish f = new Walleye();
Walleye w = new Walleye();
Bluegill b = new Bluegill();
if (f instanceof Perch)
System.out.print("f-p ");
if (w instanceof Fish)
System.out.print("w-f ");
if (b instanceof Fish)
System.out.print("b-f ");
}
}
What is the result?
: 결과는 무엇인가?
A. w-f
B. f-p w-f
C. w-f b-f
D. f-p w-f b-f
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: B
QUESTION 45
Given:
1. package com.company.application;
2.
3. public class MainClass {
4. public static void main(String[] args) {
5. }
6. }
And MainClass exists in the /apps/com/company/application directory. Assume the CLASSPATH environment variable is set to "." (current directory). Which two java commands entered at the command line will run MainClass? (Choose two.)
A. java MainClass if run from the /apps directory
B. java com.company.application.MainClass if run from the /apps directory
C. java -classpath /apps com.company.application.MainClass if run from any directory
D. java -classpath . MainClass if run from the /apps/com/company/application directory
E. java -classpath /apps/com/company/application:. MainClass if run from the /apps directory
F. java com.company.application.MainClass if run from the /apps/com/company/application directory
Answer: BC
QUESTION 46
Given
class Foo {
static void alpha() {
/* more code here */
}
void beta() {
/* more code here */
}
}
Which two statements are true? (Choose two.)
: 사실인 문장 2개는? (2개를 고르시오.)
A. Foo.beta() is a valid invocation of beta().
B. Foo.alpha() is a valid invocation of alpha().
C. Method beta() can directly call method alpha().
D. Method alpha() can directly call method beta().
Answer: BC
QUESTION 47
Given:
1. public class TestSeven extends Thread {
2. private static int x;
3. public synchronized void doThings() {
4. int current = x;
5. current++;
6. x = current;
7. }
8. public void run() {
9. doThings();
10. }
11. }
Which statement is true?
: 사실인 문장은?
A. Compilation fails.
B. An exception is thrown at runtime.
C. Synchronizing the run() method would make the class thread-safe.
D. The data in variable x are protected from concurrent access problems.
E. Declaring the doThings() method as static would make the class thread-safe.
F. Wrapping the statements within doThings() in a synchronized(new Object()) { } block would make the class thread-safe.
Answer: E
QUESTION 48
Given that the current directory is empty, and that the user has read and write privileges to the current directory, and the following:
1. import java.io.*;
2. public class Maker {
3. public static void main(String[] args) {
4. File dir = new File("dir");
5. File f = new File(dir, "f");
6. }
7. }
Which statement is true?
: 사실인 문장은?
A. Compilation fails.
B. Nothing is added to the file system.
C. Only a new file is created on the file system.
D. Only a new directory is created on the file system.
E. Both a new file and a new directory are created on the file system.
Answer: B
QUESTION 49
Given:
NumberFormat nf = NumberFormat.getInstance();
nf.setMaximumFractionDigits(4);
nf.setMinimumFractionDigits(2);
String a = nf.format(3.1415926);
String b = nf.format(2);
Which two statements are true about the result if the default locale is Locale.US? (Choose two.)
: 디폴트 지역이 Locale.US 일 경우 결과에 대해서 사실인 2 문장은? (2개를 고르시오.)
A. The value of b is 2.
B. The value of a is 3.14.
C. The value of b is 2.00.
D. The value of a is 3.141.
E. The value of a is 3.1415.
F. The value of a is 3.1416.
G. The value of b is 2.0000.
Answer: CF
QUESTION 50
Which three statements concerning the use of the java.io.Serializable interface are true? (Choose three.)
: java.io.Serializable 인터페이스 사용의 사실에 관한 3가지 문장은? (3개를 고르시오.)
A. Objects from classes that use aggregation cannot be serialized.
B. An object serialized on one JVM can be successfully deserialized on a different JVM.
C. The values in fields with the volatile modifier will NOT survive serialization and deserialization.
D. The values in fields with the transient modifier will NOT survive serialization and deserialization.
E. It is legal to serialize an object of a type that has a supertype that does NOT implement java.io.Serializable.
Answer: BDE
QUESTION 51
Given:
12. String csv = "Sue,5,true,3";
13. Scanner scanner = new Scanner( csv );
14. scanner.useDelimiter(",");
15. int age = scanner.nextInt();
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. After line 15, the value of age is 5.
C. After line 15, the value of age is 3.
D. An exception is thrown at runtime.
Answer: D
QUESTION 52
Given that c is a reference to a valid java.io.Console object, which two code fragments read a line of text from the console? (Choose two.)
: c 를 java.io.Console 개체에 대한 유효한 참조라고 한다면, 콘솔에서 한 줄의 텍스트를 읽을 수 있는 두 개의 코드 조각은? (2개를 고르시오.)
A. String s = c.readLine();
B. char[] c = c.readLine();
C. String s = c.readConsole();
D. char[] c = c.readConsole();
E. String s = c.readLine("%s", "name ");
F. char[] c = c.readLine("%s", "name ");
Answer: AE
QUESTION 53
Given:
11. String test = "a1b2c3";
12. String[] tokens = test.split("\\d");
13. for(String s: tokens) System.out.print(s + " ");
What is the result?
: 결과는 무엇인가?
A. a b c
B. 1 2 3
C. a1b2c3
D. a1 b2 c3
E. Compilation fails.
F. The code runs with no output.
G. An exception is thrown at runtime.
Answer: A
QUESTION 54
Given:
33. Date d = new Date(0);
34. String ds = "December 15, 2004";
35. // insert code here
36. try {
37. d = df.parse(ds);
38. }
39. catch(ParseException e) {
40. System.out.println("Unable to parse " + ds);
41. }
42. // insert code here too
What creates the appropriate DateFormat object and adds a day to the Date object?
: 날짜 형식 객체를 만들고 날짜 객체에 요일을 더하는 적절한 것은 무엇인가?
A. 35. DateFormat df = DateFormat.getDateFormat();
42. d.setTime( (60 * 60 * 24) + d.getTime());
B. 35. DateFormat df = DateFormat.getDateInstance();
42. d.setTime( (1000 * 60 * 60 * 24) + d.getTime());
C. 35. DateFormat df = DateFormat.getDateFormat();
42. d.setLocalTime( (1000*60*60*24) + d.getLocalTime());
D. 35. DateFormat df = DateFormat.getDateInstance();
42. d.setLocalTime( (60 * 60 * 24) + d.getLocalTime());
Answer: B
QUESTION 55
Given:
import java.util.*;
public class Quest {
public static void main(String[] args) {
String[] colors = {"blue", "red", "green", "yellow", "orange"};
Arrays.sort(colors);
int s2 = Arrays.binarySearch(colors, "orange");
int s3 = Arrays.binarySearch(colors, "violet");
System.out.println(s2 + " " + s3);
}
}
What is the result?
: 결과는 무엇인가?
A. 2 -1
B. 2 -4
C. 2 -5
D. 3 -1
E. 3 -4
F. 3 -5
G. Compilation fails.
H. An exception is thrown at runtime.
Answer: C
QUESTION 56
Given:
static void test() {
try {
String x = null;
System.out.print(x.toString() + " ");
}
finally { System.out.print("finally "); }
}
public static void main(String[] args) {
try { test(); }
catch (Exception ex) { System.out.print("exception "); }
}
What is the result?
: 결과는 무엇인가?
A. null
B. finally
C. null finally
D. Compilation fails.
E. finally exception
Answer: E
QUESTION 57
Given:
public static Collection get() {
Collection sorted = new LinkedList();
sorted.add("B");
sorted.add("C");
sorted.add("A");
return sorted;
}
public static void main(String[] args) {
for (Object obj: get()) {
System.out.print(obj + ", ");
}
}
What is the result?
: 결과는 무엇인가?
A. A, B, C,
B. B, C, A,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: B
QUESTION 58
Given:
public static Iterator reverse(List list) {
Collections.reverse(list);
return list.iterator();
}
public static void main(String[] args) {
List list = new ArrayList();
list.add("1");
list.add("2");
list.add("3");
for (Object obj: reverse(list))
System.out.print(obj + ", ");
}
What is the result?
: 결과는 무엇인가?
A. 3, 2, 1,
B. 1, 2, 3,
C. Compilation fails.
D. The code runs with no output.
E. An exception is thrown at runtime.
Answer: C
QUESTION 59
Given:
public class Base {
public static final String FOO = "foo";
public static void main(String[] args) {
Base b = new Base();
Sub s = new Sub();
System.out.print(Base.FOO);
System.out.print(Sub.FOO);
System.out.print(b.FOO);
System.out.print(s.FOO);
System.out.print(((Base) s).FOO);
}
}
class Sub extends Base {
public static final String FOO = "bar";
}
What is the result?
: 결과는 무엇인가?
A. foofoofoofoofoo
B. foobarfoobarbar
C. foobarfoofoofoo
D. foobarfoobarfoo
E. barbarbarbarbar
F. foofoofoobarbar
G. foofoofoobarfoo
Answer: D
QUESTION 60
Given:
1. public interface A { public void m1(); }
2.
3. class B implements A { }
4. class C implements A { public void m1() { } }
5. class D implements A { public void m1(int x) { } }
6. abstract class E implements A { }
7. abstract class F implements A { public void m1() { } }
8. abstract class G implements A { public void m1(int x) { } }
What is the result?
: 결과는 무엇인가?
A. Compilation succeeds.
B. Exactly one class does NOT compile.
C. Exactly two classes do NOT compile.
D. Exactly four classes do NOT compile.
E. Exactly three classes do NOT compile.
Answer: C
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
extensive
aj.형용사 아주 넓은, 대규모의
kidney
n.명사 신장, 콩팥
receiver
n.명사 수화기
presentation
n.명사 제출, 제시; 수여, 증정
then again
그렇지 않고 또, 또 한편으로는
OCJP - 1Z0-851(C-2) 공부하자!
Name : OCJP Study
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 21
Click the Exhibit button.
class Computation extends Thread {
private int num;
private boolean isComplete;
private int result;
public Computation(int num){ this.num = num; }
public synchronized void run() {
result = num * 2;
isComplete = true;
notify();
}
public synchronized int getResult() {
while ( ! isComplete ){
try {
wait();
} catch (InterruptedException e) {}
}
return result;
}
public static void main(String[] args) {
Computation[] computations = new Computation[4];
for (int i = 0; i < computations.length; i++) {
computations[i] = new Computation(i);
computations[i].start();
}
for (Computation c : computations) {
System.out.println(c.getResult() + " ");
}
}
}
What is the result?
: 결과는 무엇인가?
A. The code will deadlock.
B. The code may run with no output.
C. An exception is thrown at runtime.
D. The code may run with output "0 6".
E. The code may run with output "2 0 6 4".
F. The code may run with output "0 2 4 6".
Answer: F
QUESTION 22
Which two code fragments will execute the method doStuff() in a separate thread? (Choose two.)
: 별도의 스레드에서 doStuff() 메소드를 실행하는 코드 조각 2개는? (2개를 고르시요.)
A. new Thread() {
public void run() { doStuff(); } };
B. new Thread() {
public void start() { doStuff(); } };
C. new Thread() {
public void start() { doStuff(); } }.run();
D. new Thread() {
public void run() { doStuff(); } }.start();
E. new Thread(new Runnable() {
public void run() { doStuff(); } }).run();
F. new Thread(new Runnable() {
public void run() { doStuff(); } }).start();
Answer: DF
QUESTION 23
Given:
public class Person {
private String name;
public Person(String name) {
this.name = name;
}
public boolean equals(Object o) {
if ( ! ( o instanceof Person) ) return false;
Person p = (Person) o;
return p.name.equals(this.name);
}
}
Which statement is true?
: 사실인 문장은?
A. Compilation fails because the hashCode method is not overridden.
B. A HashSet could contain multiple Person objects with the same name.
C. All Person objects will have the same hash code because the hashCode method is not overridden.
D. If a HashSet contains more than one Person object with name="Fred", then removing another Person, also with name="Fred", will remove them all.
Answer: B
QUESTION 24
Given:
import java.util.*;
public class SortOf {
public static void main(String[] args) {
ArrayList<Integer> a = new ArrayList<Integer>();
a.add(1); a.add(5); a.add(3);
Collections.sort(a);
a.add(2);
Collections.reverse(a);
System.out.println(a);
}
}
What is the result?
: 결과는 무엇인가?
A. [1, 2, 3, 5]
B. [2, 1, 3, 5]
C. [2, 5, 3, 1]
D. [5, 3, 2, 1]
E. [1, 3, 5, 2]
F. Compilation fails.
G. An exception is thrown at runtime.
Answer: C
QUESTION 25
Given:
public class Person {
private name;
public Person(String name) {
this.name = name;
}
public int hashCode() {
return 420;
}
}
Which statement is true?
: 사실인 문장은?
A. The time to find the value from HashMap with a Person key depends on the size of the map.
B. Deleting a Person key from a HashMap will delete all map entries for all keys of type Person.
C. Inserting a second Person object into a HashSet will cause the first Person object to be removed as a duplicate.
D. The time to determine whether a Person object is contained in a HashSet is constant and does NOT depend on the size of the map.
Answer: A
QUESTION 26
Given:
public class Drink implements Comparable {
public String name;
public int compareTo(Object o) {
return 0;
}
}
and:
Drink one = new Drink();
Drink two = new Drink();
one.name= "Coffee";
two.name= "Tea";
TreeSet set = new TreeSet();
set.add(one);
set.add(two);
A programmer iterates over the TreeSet and prints the name of each Drink object.
What is the result?
: 한 프로그래머가 TreeSet을 처음부터 끝까지 반복하고 각 Drink 개체의 이름을 출력한다.
결과는 무엇인가?
A. Tea
B. Coffee
C. Coffee
Tea
D. Compilation fails.
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: B
QUESTION 27
A programmer must create a generic class MinMax and the type parameter of MinMax must implement Comparable. Which implementation of MinMax will compile?
A. class MinMax<E extends Comparable<E>> {
E min = null;
E max = null;
public MinMax() {}
public void put(E value) { /* store min or max */ }
B. class MinMax<E implements Comparable<E>> {
E min = null;
E max = null;
public MinMax() {}
public void put(E value) { /* store min or max */ }
C. class MinMax<E extends Comparable<E>> {
<E> E min = null;
<E> E max = null;
public MinMax() {}
public <E> void put(E value) { /* store min or max */ }
D. class MinMax<E implements Comparable<E>> {
<E> E min = null;
<E> E max = null;
public MinMax() {}
public <E> void put(E value) { /* store min or max */ }
Answer: A
QUESTION 28
Given:
1. import java.util.*;
2. public class Example {
3. public static void main(String[] args) {
4. // insert code here
5. set.add(new Integer(2));
6. set.add(new Integer(1));
7. System.out.println(set);
8. }
9. }
Which code, inserted at line 4, guarantees that this program will output [1, 2]?
: 4라인에 삽입하여, 이 프로그램에서 [1, 2] 출력이 나오도록 하는 코드는?
A. Set set = new TreeSet();
B. Set set = new HashSet();
C. Set set = new SortedSet();
D. List set = new SortedList();
E. Set set = new LinkedHashSet();
Answer: A
QUESTION 29
Given:
05. class A {
06. void foo() throws Exception { throw new Exception(); }
07. }
08. class SubB2 extends A {
09. void foo() { System.out.println("B "); }
10. }
11. class Tester {
12. public static void main(String[] args) {
13. A a = new SubB2();
14. a.foo();
15. }
16. }
What is the result?
: 결과는 무엇인가?
A. B
B. B, followed by an Exception.
C. Compilation fails due to an error on line 9.
D. Compilation fails due to an error on line 14.
E. An Exception is thrown with no other output.
Answer: D
QUESTION 30
Given:
1. public class Breaker {
2. static String o = "";
3.
4. public static void main(String[] args) {
5. z: o = o + 2;
6. for (int x = 3; x < 8; x++) {
7. if (x == 4)
8. break;
9. if (x == 6)
10. break z;
11. o = o + x;
12. }
13. System.out.println(o);
14. }
15. }
What is the result?
: 결과는 무엇인가?
A. 23
B. 234
C. 235
D. 2345
E. 2357
F. 23457
G. Compilation fails.
Answer: G
QUESTION 31
Given:
11. public void go(int x) {
12. assert (x > 0);
13. switch(x) {
14. case 2: ;
15. default: assert false;
16. }
17. }
18. private void go2(int x) { assert (x < 0); }
Which statement is true?
: 사실인 문장은?
A. All of the assert statements are used appropriately.
B. Only the assert statement on line 12 is used appropriately.
C. Only the assert statement on line 15 is used appropriately.
D. Only the assert statement on line 18 is used appropriately.
E. Only the assert statements on lines 12 and 15 are used appropriately.
F. Only the assert statements on lines 12 and 18 are used appropriately.
G. Only the assert statements on lines 15 and 18 are used appropriately.
Answer: G
QUESTION 32
Given:
1. public static void main(String[] args) {
2. try {
3. args = null;
4. args[0] = "test";
5. System.out.println(args[0]);
6. } catch (Exception ex) {
7. System.out.println("Exception");
8. } catch (NullPointerException npe) {
9. System.out.println("NullPointerException");
10. }
11. }
What is the result?
: 결과는 무엇인가?
A. test
B. Exception
C. Compilation fails.
D. NullPointerException
Answer: C
QUESTION 33
Given:
1. public static void main(String[] args) {
2. for (int i = 0; i <= 10; i++) {
3. if (i > 6) break;
4. }
5. System.out.println(i);
6. }
What is the result?
: 결과는 무엇인가?
A. 6
B. 7
C. 10
D. 11
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: E
QUESTION 34
Given:
11. public void testIfA() {
12. if (testIfB("True")) {
13. System.out.println("True");
14. } else {
15. System.out.println("Not true");
16. }
17. }
18. public Boolean testIfB(String str) {
19. return Boolean.valueOf(str);
20. }
What is the result when method testIfA is invoked?
: testIfA 메소드가 호출될 때, 결과는 무엇인가?
A. True
B. Not true
C. An exception is thrown at runtime.
D. Compilation fails because of an error at line 12.
E. Compilation fails because of an error at line 19.
Answer: A
QUESTION 35
Which can appropriately be thrown by a programmer using Java SE technology to create a desktop application?
A. ClassCastException
B. NullPointerException
C. NoClassDefFoundError
D. NumberFormatException
E. ArrayIndexOutOfBoundsException
Answer: D
QUESTION 36
Which two code fragments are most likely to cause a StackOverflowError? (Choose two.)
A. int []x = {1,2,3,4,5};
for(int y = 0; y < 6; y++)
System.out.println(x[y]);
B. static int[] x = {7,6,5,4};
static { x[1] = 8; x[4] = 3; }
C. for(int y = 10; y < 10; y++)
doStuff(y);
D. void doOne(int x) { doTwo(x); }
void doTwo(int y) { doThree(y); }
void doThree(int z) { doTwo(z); }
E. for(int x = 0; x < 1000000000; x++)
doStuff(x);
F. void counter(int i) { counter(++i); }
Answer: DF
QUESTION 37
Given:
04. public class Tahiti {
05. Tahiti t;
06.
07. public static void main(String[] args) {
08. Tahiti t = new Tahiti();
09. Tahiti t2 = t.go(t);
10. t2 = null;
11. // more code here
12. }
13.
14. Tahiti go(Tahiti t) {
15. Tahiti t1 = new Tahiti();
16. Tahiti t2 = new Tahiti();
17. t1.t = t2;
18. t2.t = t1;
19. t.t = t2;
20. return t1;
21. }
22. }
When line 11 is reached, how many objects are eligible for garbage collection?
: 11라인에 도달했을 때, garbage collection을 받는 개체는 몇 개인가?
A. 0
B. 1
C. 2
D. 3
E. Compilation fails.
Answer: A
QUESTION 38
Given:
interface Animal {
void makeNoise();
}
class Horse implements Animal {
Long weight = 1200L;
public void makeNoise() {
System.out.println("whinny");
}
}
01. public class Icelandic extends Horse {
02. public void makeNoise() {
03. System.out.println("vinny");
04. }
05.
06. public static void main(String[] args) {
07. Icelandic i1 = new Icelandic();
08. Icelandic i2 = new Icelandic();
09. Icelandic i3 = new Icelandic();
10. i3 = i1;
11. i1 = i2;
12. i2 = null;
13. i3 = i1;
14. }
15. }
When line 14 is reached, how many objects are eligible for the garbage collector?
: 14라인에 도달했을 때, garbage collection을 받는 개체는 몇 개인가?
A. 0
B. 1
C. 2
D. 3
E. 4
F. 6
Answer: E
QUESTION 39
Given:
11. public class Commander {
12. public static void main(String[] args) {
13. String myProp = /* insert code here */
14. System.out.println(myProp);
15. }
16. }
and the command line: java -Dprop.custom=gobstopper Commander
Which two, placed on line 13, will produce the output gobstopper? (Choose two.)
: 13라인에 놓아 gobstopper 출력이 생성되는 2개는? (2개를 고르시오.)
A. System.load("prop.custom");
B. System.getenv("prop.custom");
C. System.property("prop.custom");
D. System.getProperty("prop.custom");
E. System.getProperties().getProperty("prop.custom");
Answer: DE
QUESTION 40
Given:
1. public class ItemTest {
2. private final int id;
3.
4. public ItemTest(int id) {
5. this.id = id;
6. }
7.
8. public void updateId(int newId) {
9. id = newId;
10. }
11.
12. public static void main(String[] args) {
13. ItemTest fa = new ItemTest(42);
14. fa.updateId(69);
15. System.out.println(fa.id);
16. }
17. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The attribute id in the ItemTest object remains unchanged.
D. The attribute id in the ItemTest object is modified to the new value.
E. A new ItemTest object is created with the preferred value in the id attribute.
Answer: A
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
improvement
n.명사 향상
petition
n.명사 진정(서)
upkeep
n.명사 (건물 등의) 유지
lacquer
n.명사 래커(광택제)
and then
그러고는, 그런 다음
Category : Software
Purpose : JAVA 공부하면서 OCJP 가 합격이 되도록 비나이다.
compatibility : ...
Etc : eclipse
공부한 거는 Post 하자.!!!
JAVA도 공부하면서 OCJP 도 한번에 합격하시기를...
지금 이글을 읽을 정도로 자신의 시간을 투자하는 사람이라면 합격은 당연한것인가. 흠.
그럼 시작.
QUESTION 21
Click the Exhibit button.
class Computation extends Thread {
private int num;
private boolean isComplete;
private int result;
public Computation(int num){ this.num = num; }
public synchronized void run() {
result = num * 2;
isComplete = true;
notify();
}
public synchronized int getResult() {
while ( ! isComplete ){
try {
wait();
} catch (InterruptedException e) {}
}
return result;
}
public static void main(String[] args) {
Computation[] computations = new Computation[4];
for (int i = 0; i < computations.length; i++) {
computations[i] = new Computation(i);
computations[i].start();
}
for (Computation c : computations) {
System.out.println(c.getResult() + " ");
}
}
}
What is the result?
: 결과는 무엇인가?
A. The code will deadlock.
B. The code may run with no output.
C. An exception is thrown at runtime.
D. The code may run with output "0 6".
E. The code may run with output "2 0 6 4".
F. The code may run with output "0 2 4 6".
Answer: F
QUESTION 22
Which two code fragments will execute the method doStuff() in a separate thread? (Choose two.)
: 별도의 스레드에서 doStuff() 메소드를 실행하는 코드 조각 2개는? (2개를 고르시요.)
A. new Thread() {
public void run() { doStuff(); } };
B. new Thread() {
public void start() { doStuff(); } };
C. new Thread() {
public void start() { doStuff(); } }.run();
D. new Thread() {
public void run() { doStuff(); } }.start();
E. new Thread(new Runnable() {
public void run() { doStuff(); } }).run();
F. new Thread(new Runnable() {
public void run() { doStuff(); } }).start();
Answer: DF
QUESTION 23
Given:
public class Person {
private String name;
public Person(String name) {
this.name = name;
}
public boolean equals(Object o) {
if ( ! ( o instanceof Person) ) return false;
Person p = (Person) o;
return p.name.equals(this.name);
}
}
Which statement is true?
: 사실인 문장은?
A. Compilation fails because the hashCode method is not overridden.
B. A HashSet could contain multiple Person objects with the same name.
C. All Person objects will have the same hash code because the hashCode method is not overridden.
D. If a HashSet contains more than one Person object with name="Fred", then removing another Person, also with name="Fred", will remove them all.
Answer: B
QUESTION 24
Given:
import java.util.*;
public class SortOf {
public static void main(String[] args) {
ArrayList<Integer> a = new ArrayList<Integer>();
a.add(1); a.add(5); a.add(3);
Collections.sort(a);
a.add(2);
Collections.reverse(a);
System.out.println(a);
}
}
What is the result?
: 결과는 무엇인가?
A. [1, 2, 3, 5]
B. [2, 1, 3, 5]
C. [2, 5, 3, 1]
D. [5, 3, 2, 1]
E. [1, 3, 5, 2]
F. Compilation fails.
G. An exception is thrown at runtime.
Answer: C
QUESTION 25
Given:
public class Person {
private name;
public Person(String name) {
this.name = name;
}
public int hashCode() {
return 420;
}
}
Which statement is true?
: 사실인 문장은?
A. The time to find the value from HashMap with a Person key depends on the size of the map.
B. Deleting a Person key from a HashMap will delete all map entries for all keys of type Person.
C. Inserting a second Person object into a HashSet will cause the first Person object to be removed as a duplicate.
D. The time to determine whether a Person object is contained in a HashSet is constant and does NOT depend on the size of the map.
Answer: A
QUESTION 26
Given:
public class Drink implements Comparable {
public String name;
public int compareTo(Object o) {
return 0;
}
}
and:
Drink one = new Drink();
Drink two = new Drink();
one.name= "Coffee";
two.name= "Tea";
TreeSet set = new TreeSet();
set.add(one);
set.add(two);
A programmer iterates over the TreeSet and prints the name of each Drink object.
What is the result?
: 한 프로그래머가 TreeSet을 처음부터 끝까지 반복하고 각 Drink 개체의 이름을 출력한다.
결과는 무엇인가?
A. Tea
B. Coffee
C. Coffee
Tea
D. Compilation fails.
E. The code runs with no output.
F. An exception is thrown at runtime.
Answer: B
QUESTION 27
A programmer must create a generic class MinMax and the type parameter of MinMax must implement Comparable. Which implementation of MinMax will compile?
A. class MinMax<E extends Comparable<E>> {
E min = null;
E max = null;
public MinMax() {}
public void put(E value) { /* store min or max */ }
B. class MinMax<E implements Comparable<E>> {
E min = null;
E max = null;
public MinMax() {}
public void put(E value) { /* store min or max */ }
C. class MinMax<E extends Comparable<E>> {
<E> E min = null;
<E> E max = null;
public MinMax() {}
public <E> void put(E value) { /* store min or max */ }
D. class MinMax<E implements Comparable<E>> {
<E> E min = null;
<E> E max = null;
public MinMax() {}
public <E> void put(E value) { /* store min or max */ }
Answer: A
QUESTION 28
Given:
1. import java.util.*;
2. public class Example {
3. public static void main(String[] args) {
4. // insert code here
5. set.add(new Integer(2));
6. set.add(new Integer(1));
7. System.out.println(set);
8. }
9. }
Which code, inserted at line 4, guarantees that this program will output [1, 2]?
: 4라인에 삽입하여, 이 프로그램에서 [1, 2] 출력이 나오도록 하는 코드는?
A. Set set = new TreeSet();
B. Set set = new HashSet();
C. Set set = new SortedSet();
D. List set = new SortedList();
E. Set set = new LinkedHashSet();
Answer: A
QUESTION 29
Given:
05. class A {
06. void foo() throws Exception { throw new Exception(); }
07. }
08. class SubB2 extends A {
09. void foo() { System.out.println("B "); }
10. }
11. class Tester {
12. public static void main(String[] args) {
13. A a = new SubB2();
14. a.foo();
15. }
16. }
What is the result?
: 결과는 무엇인가?
A. B
B. B, followed by an Exception.
C. Compilation fails due to an error on line 9.
D. Compilation fails due to an error on line 14.
E. An Exception is thrown with no other output.
Answer: D
QUESTION 30
Given:
1. public class Breaker {
2. static String o = "";
3.
4. public static void main(String[] args) {
5. z: o = o + 2;
6. for (int x = 3; x < 8; x++) {
7. if (x == 4)
8. break;
9. if (x == 6)
10. break z;
11. o = o + x;
12. }
13. System.out.println(o);
14. }
15. }
What is the result?
: 결과는 무엇인가?
A. 23
B. 234
C. 235
D. 2345
E. 2357
F. 23457
G. Compilation fails.
Answer: G
QUESTION 31
Given:
11. public void go(int x) {
12. assert (x > 0);
13. switch(x) {
14. case 2: ;
15. default: assert false;
16. }
17. }
18. private void go2(int x) { assert (x < 0); }
Which statement is true?
: 사실인 문장은?
A. All of the assert statements are used appropriately.
B. Only the assert statement on line 12 is used appropriately.
C. Only the assert statement on line 15 is used appropriately.
D. Only the assert statement on line 18 is used appropriately.
E. Only the assert statements on lines 12 and 15 are used appropriately.
F. Only the assert statements on lines 12 and 18 are used appropriately.
G. Only the assert statements on lines 15 and 18 are used appropriately.
Answer: G
QUESTION 32
Given:
1. public static void main(String[] args) {
2. try {
3. args = null;
4. args[0] = "test";
5. System.out.println(args[0]);
6. } catch (Exception ex) {
7. System.out.println("Exception");
8. } catch (NullPointerException npe) {
9. System.out.println("NullPointerException");
10. }
11. }
What is the result?
: 결과는 무엇인가?
A. test
B. Exception
C. Compilation fails.
D. NullPointerException
Answer: C
QUESTION 33
Given:
1. public static void main(String[] args) {
2. for (int i = 0; i <= 10; i++) {
3. if (i > 6) break;
4. }
5. System.out.println(i);
6. }
What is the result?
: 결과는 무엇인가?
A. 6
B. 7
C. 10
D. 11
E. Compilation fails.
F. An exception is thrown at runtime.
Answer: E
QUESTION 34
Given:
11. public void testIfA() {
12. if (testIfB("True")) {
13. System.out.println("True");
14. } else {
15. System.out.println("Not true");
16. }
17. }
18. public Boolean testIfB(String str) {
19. return Boolean.valueOf(str);
20. }
What is the result when method testIfA is invoked?
: testIfA 메소드가 호출될 때, 결과는 무엇인가?
A. True
B. Not true
C. An exception is thrown at runtime.
D. Compilation fails because of an error at line 12.
E. Compilation fails because of an error at line 19.
Answer: A
QUESTION 35
Which can appropriately be thrown by a programmer using Java SE technology to create a desktop application?
A. ClassCastException
B. NullPointerException
C. NoClassDefFoundError
D. NumberFormatException
E. ArrayIndexOutOfBoundsException
Answer: D
QUESTION 36
Which two code fragments are most likely to cause a StackOverflowError? (Choose two.)
A. int []x = {1,2,3,4,5};
for(int y = 0; y < 6; y++)
System.out.println(x[y]);
B. static int[] x = {7,6,5,4};
static { x[1] = 8; x[4] = 3; }
C. for(int y = 10; y < 10; y++)
doStuff(y);
D. void doOne(int x) { doTwo(x); }
void doTwo(int y) { doThree(y); }
void doThree(int z) { doTwo(z); }
E. for(int x = 0; x < 1000000000; x++)
doStuff(x);
F. void counter(int i) { counter(++i); }
Answer: DF
QUESTION 37
Given:
04. public class Tahiti {
05. Tahiti t;
06.
07. public static void main(String[] args) {
08. Tahiti t = new Tahiti();
09. Tahiti t2 = t.go(t);
10. t2 = null;
11. // more code here
12. }
13.
14. Tahiti go(Tahiti t) {
15. Tahiti t1 = new Tahiti();
16. Tahiti t2 = new Tahiti();
17. t1.t = t2;
18. t2.t = t1;
19. t.t = t2;
20. return t1;
21. }
22. }
When line 11 is reached, how many objects are eligible for garbage collection?
: 11라인에 도달했을 때, garbage collection을 받는 개체는 몇 개인가?
A. 0
B. 1
C. 2
D. 3
E. Compilation fails.
Answer: A
QUESTION 38
Given:
interface Animal {
void makeNoise();
}
class Horse implements Animal {
Long weight = 1200L;
public void makeNoise() {
System.out.println("whinny");
}
}
01. public class Icelandic extends Horse {
02. public void makeNoise() {
03. System.out.println("vinny");
04. }
05.
06. public static void main(String[] args) {
07. Icelandic i1 = new Icelandic();
08. Icelandic i2 = new Icelandic();
09. Icelandic i3 = new Icelandic();
10. i3 = i1;
11. i1 = i2;
12. i2 = null;
13. i3 = i1;
14. }
15. }
When line 14 is reached, how many objects are eligible for the garbage collector?
: 14라인에 도달했을 때, garbage collection을 받는 개체는 몇 개인가?
A. 0
B. 1
C. 2
D. 3
E. 4
F. 6
Answer: E
QUESTION 39
Given:
11. public class Commander {
12. public static void main(String[] args) {
13. String myProp = /* insert code here */
14. System.out.println(myProp);
15. }
16. }
and the command line: java -Dprop.custom=gobstopper Commander
Which two, placed on line 13, will produce the output gobstopper? (Choose two.)
: 13라인에 놓아 gobstopper 출력이 생성되는 2개는? (2개를 고르시오.)
A. System.load("prop.custom");
B. System.getenv("prop.custom");
C. System.property("prop.custom");
D. System.getProperty("prop.custom");
E. System.getProperties().getProperty("prop.custom");
Answer: DE
QUESTION 40
Given:
1. public class ItemTest {
2. private final int id;
3.
4. public ItemTest(int id) {
5. this.id = id;
6. }
7.
8. public void updateId(int newId) {
9. id = newId;
10. }
11.
12. public static void main(String[] args) {
13. ItemTest fa = new ItemTest(42);
14. fa.updateId(69);
15. System.out.println(fa.id);
16. }
17. }
What is the result?
: 결과는 무엇인가?
A. Compilation fails.
B. An exception is thrown at runtime.
C. The attribute id in the ItemTest object remains unchanged.
D. The attribute id in the ItemTest object is modified to the new value.
E. A new ItemTest object is created with the preferred value in the id attribute.
Answer: A
이해가 안되는 문제가 있다면 글 남겨주세요. 저도 JAVA 공부하면서 같이 해결해요~
Today.
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