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?()
第1题:
以下程序的输出结果是_____。
include<iostream.h>
class object
{ private:
int val;
public:
object( ) ;
object(int i) ;
~object( ) ;};
object: :object( )
{ val=0;
cout < < "Default constructor for object" < < endl;}
object: :object(int i)
{ val=i;
cout < < "Constructor for object" < < val < < endl;}
object: :~object( )
{ cout < < "Destructor for object" < < val < < endl;}
class container{ private:
object one;
object two;
int data;
public:
container( ) ;
container(int i,int j,int k) ;
~container( ) ;};
container: :container( )
{ data=0;
cout < < "Default constructor for container" < < endl;}
container: :container(int i,int j,int k) :two(i) ,one(j)
{ data=k;
cout < < "Constructor for container" < < endl;}
container: :~container( )
{ cout < < "Destructor for container" < < endl;}
void main( )
{ container anObj(5,6,10) ;}
第2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?()
第3题:
在J2EE中,以下是firePropertyChange的原型,正确的是()。
第4题:
下列代码正确的是哪项?()
第5题:
Given an ActionEvent, which method allows you to identify the affected Component?()
第6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?()
第7题:
Public class getClass()
Public Object getSource()
Public Component getSource()
Public Component getTarget()
Public Component getComponent()
Public Component getTargetComponent()
第8题:
Just after line 5.
Just after line 6.
Just after line 7.
Just after line 8(that is, as the method returns).
第9题:
public class Session implements Runnable, Clonable{ public void run ();public Object clone () ; }
public class Session extends Runnable, Cloneable { public void run() {/*dosomething*/} public Object clone() {/*make a copy*/} }
public abstract class Session implements Runnable, Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }
public class Session implements Runnable, implements Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }
第10题:
Point p = Line.getPoint();
Line.Point p = Line.getPoint();
Point p = (new Line()).getPoint();
Line.Point p = (new Line()).getPoint();
第11题:
public int compareTo(Object o) {/*mode code here*/}
public int compareTo(Score other) {/*more code here*/}
public int compare(Score s1,Score s2){/*more code here*/}
public int compare(Object o1,Object o2){/*more code here*/}
第12题:
public void fireVetoableChange(Object oldValue,Object newValue)
public void fireVetoableChange(String propertyName,Object newValue)
public void fireVetoableChange(String propertyName, Object oldValue ,Object newValue)throws PropertyVetoException
public void fireVetoableChange(String propertyName, Object oldValue ,Object newValue)
第13题:
把一个对象写到一个流中相对比较简单,具体是通过调用ObjectOutputStream类的writeObject()方法实现的,那么该方法的定义为( )。
A.public final int writeObject(Object obj) throws IOException
B.public final void writeObject(Object obj) throws IOException
C.public Object writeObject(Object obj) throws IOException
D.public final Object writeObject(Object obj) throws IOException
第14题:
在j2ee中,以下是firevetoablechange方法的正确的原型的是()
第15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?()
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?()
第17题:
1.public class Test { 2.public static void main (String args[]) { 3.class Foo { 4.public int i = 3; 5.} 6.Object o = (Object) new Foo(); 7.Foo foo = (Foo)o; 8.System.out.printIn(foo. i); 9. } 10.} What is the result?()
第18题:
10. class Line { 11. public class Point { public int x,y; } 12. public Point getPoint() { return new Point(); } 13. } 14. class Triangle { 15. public Triangle() { 16. // insert code here 17. } 18. } Which code, inserted at line 16, correctly retrieves a local instance of a Point object?()
第19题:
Just after line 5.
Just after line 6.
Just after line 7.
Just after line 8(that is, as the method returns).
第20题:
Line5
Line6
Line7
Line8
Line9
Line10
第21题:
Just after line 5
Just after line 6
Just after line 7 (that is, as the method returns)
Never in this method.
第22题:
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
第23题:
Compilation will fail.
Compilation will succeed and the program will print “3”
Compilation will succeed but the program will throw a ClassCastException at line 6.
Compilation will succeed but the program will throw a ClassCastException at line 7.