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?(

题目
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.


相似考题

1.阅读下列函数说明和Java代码,将应填入(n)处的字句写在对应栏内。【说明】类Queue表示队列,类中的方法如下表所示。类Node表示队列中的元素;类EmptyQueueException给出了队列操作中的异常处理操作。public class TestMain { //主类public static viod main (String args[]){Queue q=new Queue();q.enqueue("first!");q.enqueue("second!");q.enqueue("third!");(1) {while(true)System.out.println(q.dequeue());}catch( (2) ){ }}public class Queue { //队列Node m_FirstNode;public Queue(){m_FirstNode=null;}public boolean isEmpty(){if(m_FirstNode==null)return true;else return false;}public viod enqueue(Object newNode) { //入队操作Node next=m_FirstNode;if(next==null)m_FirstNode=new Node(newNode);else{while(next.getNext()!=null)next=next.getNext();next.setNext(new node(newNode));}}public Object dequeue() (3) { //出队操作Object node;if (isEempty())(4); //队列为空, 抛出异常else{node=m_FirstNode.getObject();m_FirstNode=m_FirstNode.getNext();return node;}}}public class Node{ //队列中的元素Object m_Data;Node m_Next;public Node(Object data) {m_Data=data; m_Next=null;}public Node(Object data, Node next) {m_Data=data; m_Next=-next;}public void setObject(Object data) {m_Data=data;}public Object getObject(Object data) {return m_data;}public void setNext(Node next) {m_Next=next;}public Node getNext() {return m_Next;}}public class EmptyQueueException extends (5) { //异常处理类public EmptyQueueException() {System.out.println("队列已空! ");}}

3.阅读以下说明和Java代码,将应填入(n)处的字句写在答题纸的对应栏内。说明类Queue表示队列,类中的方法如下表所示。类Node表示队列中的元素;类EmptyQueueException 给出了队列操作中的异常处理操作。Java 代码public class TestMain{ // 主类public static void main(String args[]) {Queue q = new Queue();q.enqueue("first!");q.enqueue("second!");q.enqueue("third!");(1) {while(true)System.out.println(q. dequeue());}catch((2)) ( }}}public class Queue { // 队列Node m_FirstNode;public Queue() { m_FirstNode = null; }public boolean isEmpty() {if(m_FirstNode == null) return true;else return false;}public void enqueue(Object newNode) {// 入队操作Node next = m_FirstNode;if(next==null) m_FirstNode = new Node(newNode);else {while(next.getNext() != null) next = next.getNext();next.setNext(new Node(newNode));}}public Object dequeue() (3) {// 出队操作Object node;if (isEmpty())(4); // 队列为空,抛出异常else {node = m_FirstNode.getObject();m_FirstNode = m_FirstNode.getNext();return node;}}}public class Node { // 队列中的元素Object m_Data;Node m_Next;public Node(Object data) { m_Data = data; m_Next = null; }public Node(Object data, Node next) { m_Data = data; m_Next = next; }public void setObject(Object data) { m_Data = data; }public Object getObject0 { return m_Data; }public void setNext(Node next) { m_Next = next; }public Node getNext() { return m_Next; }}public class EmptyQueueException extends (5) { // 异常处理类public EmptyQueueException0 {System.out.println("队列已空 ! ");}}

更多“1. public class X (  2. public object m ()  {  3. object o =”相关问题
  • 第1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:D

  • 第2题:

    1. import java.util.*;  2. class ForInTest {  3. static List list = new ArrayList();  4.  5. static List getList() { return list; }  6.  7. public static void main(String [] args) {  8. list.add("a"); list.add("b"); list.add("c");  9. // insert code here  10. System.out.print(o);  11. }  12. } 第 9 行插入哪一项将输出 abc?() 

    • A、for(char o: list)
    • B、for(Object o: getList())
    • C、for(Object o: getList();)
    • D、for(Object o: o.getList())

    正确答案:B

  • 第3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4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5题:

    public class Key {  private long id1;  private long 1d2;  // 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?()

    • 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)

    正确答案:A,D

  • 第6题:

    Which three will compile and run without exception?()

    • A、private synchronized Object o;
    • B、void go() {synchronized() { /* code here */ }
    • C、public synchronized void go() { /* code here */ }
    • D、private synchronized(this) void go() { /* code here */ }
    • E、void go() {synchronized(Object.class) { /* code here */ }
    • F、void go() {Object o = new Object();synchronized(o) { /* code here */ }

    正确答案:C,E,F

  • 第7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: D
    解析: 暂无解析

  • 第9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10题:

    多选题
    Given:  1.  public class ConstOver {  2.  public constOver(int x, int y, int z) {  3.  }  4.  }   Which two overload the ConstOver Constructor?()
    A

    ConstOver() {}

    B

    protected int ConstOver(){}

    C

    private ConstOver(int z, int y, byte x ) {}

    D

    public Object ConstOver(Int x, int y, int z) {}

    E

    pubic void ConstOver (byte x, byte y, byte z) {}


    正确答案: B,D
    解析: 暂无解析

  • 第11题:

    单选题
    1. import java.util.*;  2. class ForInTest {  3. static List list = new ArrayList();  4.  5. static List getList() { return list; }  6.  7. public static void main(String [] args) {  8. list.add("a"); list.add("b"); list.add("c");  9. // insert code here  10. System.out.print(o);  11. }  12. } 第 9 行插入哪一项将输出 abc?()
    A

    for(char o: list)

    B

    for(Object o: getList())

    C

    for(Object o: getList();)

    D

    for(Object o: o.getList())


    正确答案: D
    解析: 暂无解析

  • 第12题:

    单选题
    public class Score implements Comparable {  private int wins, losses;  public Score(int w, int 1) { wins = w; losses = 1; }  public int getWins() { return wins; }  public int getLosses() { return losses; }  public String toString() {  return “”; }  // insert code here  }  Which method will complete this class?()
    A

     public int compareTo(Object o) {/*mode code here*/}

    B

     public int compareTo(Score other) {/*more code here*/}

    C

     public int compare(Score s1,Score s2){/*more code here*/}

    D

     public int compare(Object o1,Object o2){/*more code here*/}


    正确答案: B
    解析: 暂无解析

  • 第13题:

    1. public interface A {  2. public void doSomething(String thing);  3. }  1. public class AImpl implements A {  2. public void doSomething(String msg) { }  3. }  1. public class B {  2. public A doit() {  3. // more code here  4. }  5.  6. public String execute() { 7. // more code here  8. }  9. }  1. public class C extends B {  2. public AImpl doit() {  3. // more code here  4. }  5.  6. public Object execute() {  7. // more code here  8. }  9. }  Which statement is true about the classes and interfaces in the exhibit?() 

    • A、 Compilation will succeed for all classes and interfaces.
    • B、 Compilation of class C will fail because of an error in line 2.
    • C、 Compilation of class C will fail because of an error in line 6.
    • D、 Compilation of class AImpl will fail because of an error in line 2.

    正确答案:C

  • 第14题:

    下列代码正确的是哪项?() 

    • A、 public class Session implements Runnable, Clonable{   public void run ();public Object clone () ; }
    • B、 public class Session extends Runnable, Cloneable {  public void run() {/*dosomething*/}       public Object clone() {/*make a copy*/} }
    • C、 public abstract class Session implements Runnable, Clonable {       public void run() {/*do something*/}       public Object clone() {/*make a copy*/}        }
    • D、 public class Session implements Runnable, implements Clonable {       public void run() {/*do something*/}       public Object clone() {/*make a copy*/}       }

    正确答案:C

  • 第15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16题:

    Given:  1.  public class ConstOver {  2.  public constOver(int x, int y, int z) {  3.  }  4.  }   Which two overload the ConstOver Constructor?()

    • A、 ConstOver() {}
    • B、 protected int ConstOver(){}
    • C、 private ConstOver(int z, int y, byte x ) {}
    • D、 public Object ConstOver(Int x, int y, int z) {}
    • E、 pubic void ConstOver (byte x, byte y, byte z) {}

    正确答案:A,C

  • 第17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18题:

    You work as an application developer at Certkiller .com. Certkiller .com has instructed you to create a class named MetricFormula. This class will be used to compare MetricUnit and EnglishUnit objects.The MetricFormula is currently defined as follows (Line numbers are used for reference purposes only): 1. public class MetricFormula2. { 3. 4. } You need to ensure that the MetricFormula class can be used to compare the required objects. What should you do? ()

    • A、 Add the following code on line 1: : IComparable {
    • B、 Add the following code on line 1: : IComparer {
    • C、 Add the following code on line 3: public int Compare (object x, object y) {// implementation code }
    • D、 Add the following code on line 3: public int CompareTo (object obj) {// implementation code }

    正确答案:B,C

  • 第19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: A
    解析: 暂无解析

  • 第20题:

    单选题
    下列代码正确的是哪项?()
    A

     public class Session implements Runnable, Clonable{   public void run ();public Object clone () ; }

    B

     public class Session extends Runnable, Cloneable {  public void run() {/*dosomething*/}       public Object clone() {/*make a copy*/} }

    C

     public abstract class Session implements Runnable, Clonable {       public void run() {/*do something*/}       public Object clone() {/*make a copy*/}        }

    D

     public class Session implements Runnable, implements Clonable {       public void run() {/*do something*/}       public Object clone() {/*make a copy*/}       }


    正确答案: A
    解析: 暂无解析

  • 第21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: D
    解析: 暂无解析

  • 第22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23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: E
    解析: 暂无解析