单选题public class X {  public object m () {   object o = new float (3.14F);   object oa = new object [1];   oa[0]= o;   o = null;   return oa[0];   }   }   When is the float object created in line 3, eligible for garbage collection?()AJust after line 5BJust

题目
单选题
public class X {  public object m () {   object o = new float (3.14F);   object oa = new object [1];   oa[0]= o;   o = null;   return oa[0];   }   }   When is the float object created in line 3, eligible for garbage collection?()
A

 Just after line 5

B

 Just after line 6

C

 Just after line 7 (that is, as the method returns)

D

 Never in this method.


相似考题
参考答案和解析
正确答案: D
解析: 暂无解析
更多“单选题public class X {  public object m () {   object o = new float (3.14F);   object oa = new object [1];   oa[0]= o;   o = null;   return oa[0];   }   }   When is the float object created in line 3, eligible for garbage collection?()A  Just after line 5B  ”相关问题
  • 第1题:

    1. class Test {  2. private Demo d;  3. void start() {  4. d = new Demo();  5. this.takeDemo(d); 6. }  7.   8. void takeDemo(Demo demo) {  9. demo = null;  10. demo = new Demo(); 11. }  12. }  When is the Demo object, created on line 3, eligible for garbage collection?()  

    • A、 After line 5.
    • B、 After line 9.
    • C、 After the start() method completes.
    • D、 When the takeDemo() method completes.
    • E、 When the instance running this code is made eligible for garbage collection.

    正确答案:E

  • 第2题:

    12. void start() {  13. A a = new A();  14. B b = new B();  15. a.s(b);  16. b = null;  17. a = null;  18. System.out.println(“start completed”); 19. }  When is the B object, created in line 14, eligible for garbage collection?()  

    • A、 After line 16.
    • B、 After line 17.
    • C、 After line 18 (when the methods ends).
    • D、 There is no way to be absolutely certain.
    • E、 The object is NOT eligible for garbage collection.

    正确答案:D

  • 第3题:

    1.public class GC{ 2.private Objec to; 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?()

    • A、Line5
    • B、Line6
    • C、Line7
    • D、Line8
    • E、Line9
    • F、Line10

    正确答案:D

  • 第4题:

    public class Test {  public static void main(String args[]) {  class Foo {  public int i = 3; }  Object o = (Object)new Foo();   Foo foo = (Foo)o;  System.out.println(“i = “ + foo.i); }  }  What is the result?()  

    • A、 i = 3
    • B、 Compilation fails.
    • C、 A ClassCastException is thrown at line 6.
    • D、 A ClassCastException is thrown at line 7.

    正确答案:A

  • 第5题:

    public class X {   public object m () {   object o = new float (3.14F);   object oa = new object [1];   oa[0]= o;   o = null;   oa[0] = null;   return o;   }   }   When is the float object created in line 3, eligible for garbage collection?()  

    • A、 Just after line 5.
    • B、 Just after line 6.
    • C、 Just after line 7.
    • D、 Just after line 8(that is, as the method returns).

    正确答案:C

  • 第6题:

    11. class Snoochy {  12. Boochybooch;  13. public Snoochy() { booch = new Boochy(this); }  14. }  15.  16. class Boochy {  17. Snoochy snooch;  18. public Boochy(Snoochy s) { snooch = s; }  19. }  And the statements:  21. public static void main(String[] args) {  22. Snoochy snoog = new Snoochy();  23. snoog = null;  24. // more code here  25. }  Which statement is true about the objects referenced by snoog, snooch, and booch immediately after line 23 executes?() 

    • A、 None of these objects are eligible for garbage collection.
    • B、 Only the object referenced by booch is eligible for garbage collection.
    • C、 Only the object referenced by snoog is eligible for garbage collection.
    • D、 Only the object referenced by snooch is eligible for garbage collection.
    • E、 The objects referenced by snooch and booch are eligible for garbage collection.

    正确答案:E

  • 第7题:

    单选题
    10. public Object m() { 11. Object o = new Float(3.14F); 12. Object [] oa = new Object[1]; 13. oa[0] = o; 14. o = null; 15. return oa[0]; 16. } When is the Float object, created in line 11, eligible for garbage collection?()
    A

     Just after line 13.

    B

     Just after line 14.

    C

     Never in this method.

    D

     Just after line 15 (that is, as the method returns).


    正确答案: A
    解析: The correct answer to this question is C. The object is never garbage collected simply because the method returns it. Think about it, the message that receives the object might depend on it so it must be sure that the object received by the method wont be garbage collected. Only in this situation a local object  wont be eligible for garbage collection. Otherwise, a local object is eligible for garbage collection as soon as the method ends.

  • 第8题:

    单选题
    1.public class GC{ 2.private Objec to; 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?()
    A

    Line5

    B

    Line6

    C

    Line7

    D

    Line8

    E

    Line9

    F

    Line10


    正确答案: A
    解析: 暂无解析

  • 第9题:

    单选题
    11. class Snoochy {  12. Boochybooch;  13. public Snoochy() { booch = new Boochy(this); }  14. }  15.  16. class Boochy {  17. Snoochy snooch;  18. public Boochy(Snoochy s) { snooch = s; }  19. }  And the statements:  21. public static void main(String[] args) {  22. Snoochy snoog = new Snoochy();  23. snoog = null;  24. // more code here  25. }  Which statement is true about the objects referenced by snoog, snooch, and booch immediately after line 23 executes?()
    A

     None of these objects are eligible for garbage collection.

    B

     Only the object referenced by booch is eligible for garbage collection.

    C

     Only the object referenced by snoog is eligible for garbage collection.

    D

     Only the object referenced by snooch is eligible for garbage collection.

    E

     The objects referenced by snooch and booch are eligible for garbage collection.


    正确答案: B
    解析: 暂无解析

  • 第10题:

    多选题
    1. class TestA {  2. TestB b;  3. TestA() {  4. b = new TestB(this);  5. }  6. }  7. class TestB {  8. TestA a;  9. TestB(TestA a) {  10. this.a = a;  11. }  12. }  13. class TestAll {  14. public static void main (String args[]) {  15. new TestAll().makeThings(); 16. // ...code continues on  17. }  18. void makeThings() {  19. TestA test = new TestA(); 20. }  21. }  Which two statements are true after line 15, before main completes?()
    A

    Line 15 causes a stack overflow.

    B

    An exception is thrown at runtime.

    C

    The object referenced by a is eligible for garbage collection.

    D

    The object referenced by b is eligible for garbage collection.

    E

    The object referenced by a is not eligible for garbage collection.

    F

    The object referenced by b is not eligible for garbage collection.


    正确答案: C,F
    解析: This is a typical example of the island of isolation. On line 15, the two objects TestA and TestB have a reference to one an other. Therefore, the correct answers are C. and D. A key point to remember is that an object that is referenced by another object can be eligible for garbage collection if the two objects form an island of isolated objects. 

  • 第11题:

    单选题
    1. public class X {  2. public object m ()  {  3. object o = new float (3.14F);  4. object [] oa = new object [1]; 5. oa[0]= o;  6. o = null;  7. oa[0] = null;  10. return o;  9. }  10. }  When is the float object created in line 3, eligible for garbage collection?()
    A

     Just after line 5.

    B

     Just after line 6.

    C

     Just after line 7.

    D

     Just after line 8(that is, as the method returns).


    正确答案: D
    解析: 暂无解析

  • 第12题:

    单选题
    12. void start() {  13. A a = new A();  14. B b = new B();  15. a.s(b);  16. b = null;  17. a = null;  18. System.out.println(“start completed”); 19. }  When is the B object, created in line 14, eligible for garbage collection?()
    A

     After line 16.

    B

     After line 17.

    C

     After line 18 (when the methods ends).

    D

     There is no way to be absolutely certain.

    E

     The object is NOT eligible for garbage collection.


    正确答案: B
    解析: The correct answer to this question is D. The member method s is not defined so there is no way to be certain of the result. 

  • 第13题:

    10. public Object m() { 11. Object o = new Float(3.14F); 12. Object [] oa = new Object[1]; 13. oa[0] = o; 14. o = null; 15. return oa[0]; 16. } When is the Float object, created in line 11, eligible for garbage collection?()  

    • A、 Just after line 13.
    • B、 Just after line 14.
    • C、 Never in this method.
    • D、 Just after line 15 (that is, as the method returns).

    正确答案:C

  • 第14题:

    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?() 

    • A、 Line 5
    • B、 Line 6
    • C、 Line 7
    • D、 Line 8
    • E、 Line 9
    • F、 Line 10

    正确答案:D

  • 第15题:

    1. public class X (  2. public object m ()  {  3. object o = new float (3.14F);  4. object [] oa = new object [1];  5. oa[0]= o;  6. o = null;  7. return oa[0];  8. }  9. }   When is the float object created in line 3, eligible for garbage collection?()  

    • A、 Just after line 5
    • B、 Just after line 6
    • C、 Just after line 7 (that is, as the method returns)
    • D、 Never in this method.

    正确答案:D

  • 第16题:

    1. public class X {  2. public object m ()  {  3. object o = new float (3.14F);  4. object [] oa = new object [1]; 5. oa[0]= o;  6. o = null;  7. oa[0] = null;  10. return o;  9. }  10. }  When is the float object created in line 3, eligible for garbage collection?()  

    • A、 Just after line 5.
    • B、 Just after line 6.
    • C、 Just after line 7.
    • D、 Just after line 8(that is, as the method returns).

    正确答案:C

  • 第17题:

    1. class Bar { }  1. class Test {  2. Bar doBar() {  3. Bar b = new Bar();  4. return b;  5. }  6. public static void main (String args[]) {  7. Test t = new Test();  8. Bar newBar = t.doBar();  9. System.out.println(“newBar”);  10. newBar = new Bar();  11. System.out.println(“finishing”);  12. }  13. } At what point is the Bar object, created on line 3, eligible for garbage collection?()  

    • A、 After line 8.
    • B、 After line 10.
    • C、 After line 4, when doBar() completes.
    • D、 After line 11, when main() completes.

    正确答案:B

  • 第18题:

    单选题
    public class Test {   public static void main (String args) {   class Foo {   public int i = 3;  }   Object o = (Object) new Foo();   Foo foo = (Foo)o;   System.out.printIn(foo. i);  }   }   What is the result?()
    A

     Compilation will fail.

    B

     Compilation will succeed and the program will print “3”

    C

     Compilation will succeed but the program will throw a ClassCastException at line 6.

    D

     Compilation will succeed but the program will throw a ClassCastException at line 7.


    正确答案: D
    解析: 暂无解析

  • 第19题:

    单选题
    11.class Snoochy{ 12.Boochybooch; 13.public Snoochy(){booch=newBoochy(this);} 14.} 15. 16.class Boochy{ 17.Snoochy snooch; 18.public Boochy(Snoochys){snooch=s;} 19.} And the statements: 21.public static void main(String[]args){ 22.Snoochy snoog=new Snoochy(); 23.snoog=null; 24.//more code here 25.} Which statement is true about the objects referenced by snoog,snooch,and booch immediately after line 23 executes?()
    A

    None of these objects are eligible for garbage collection.

    B

    Only the object referenced by booch is eligible for garbage collection.

    C

    Only the object referenced by snoog is eligible for garbage collection.

    D

    Only the object referenced by snooch is eligible for garbage collection.

    E

    The objects referenced by snooch and booch are eligible for garbage collection.


    正确答案: C
    解析: 暂无解析

  • 第20题:

    单选题
    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?()
    A

     Line 5

    B

     Line 6

    C

     Line 7

    D

     Line 8

    E

     Line 9

    F

     Line 10


    正确答案: A
    解析: 暂无解析

  • 第21题:

    单选题
    public class Test {  public static void main(String args[]) {  class Foo {  public int i = 3; }  Object o = (Object)new Foo();   Foo foo = (Foo)o;  System.out.println(“i = “ + foo.i); }  }  What is the result?()
    A

     i = 3

    B

     Compilation fails.

    C

     A ClassCastException is thrown at line 6.

    D

     A ClassCastException is thrown at line 7.


    正确答案: D
    解析: 暂无解析

  • 第22题:

    单选题
    public class X {   public object m () {   object o = new float (3.14F);   object oa = new object [1];   oa[0]= o;   o = null;   oa[0] = null;   return o;   }   }   When is the float object created in line 3, eligible for garbage collection?()
    A

     Just after line 5.

    B

     Just after line 6.

    C

     Just after line 7.

    D

     Just after line 8(that is, as the method returns).


    正确答案: C
    解析: 暂无解析

  • 第23题:

    单选题
    public class X {  public object m () {   object o = new float (3.14F);   object oa = new object [1];   oa[0]= o;   o = null;   return oa[0];   }   }   When is the float object created in line 3, eligible for garbage collection?()
    A

     Just after line 5

    B

     Just after line 6

    C

     Just after line 7 (that is, as the method returns)

    D

     Never in this method.


    正确答案: C
    解析: 暂无解析

  • 第24题:

    单选题
    1. public class X (  2. public object m ()  {  3. object o = new float (3.14F);  4. object [] oa = new object [1];  5. oa[0]= o;  6. o = null;  7. return oa[0];  8. }  9. }   When is the float object created in line 3, eligible for garbage collection?()
    A

     Just after line 5

    B

     Just after line 6

    C

     Just after line 7 (that is, as the method returns)

    D

     Never in this method.


    正确答案: A
    解析: 暂无解析