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 me

题目
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


相似考题
参考答案和解析
正确答案: D
解析: 暂无解析
更多“1.public class GC{ 2.private Objec to; 3.private void doSome”相关问题
  • 第1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


    参考答案:D

  • 第2题:

    下列程序的运行结果是______。include class Base { public: void f(int x){cout<<“B

    下列程序的运行结果是______。

    include<iostream.h>

    class Base

    {

    public:

    void f(int x){cout<<“Base:”<<x<<endl;}

    );

    class Derived:public Base

    {

    public:

    void f(char*str){cout<<“Derived:”<<str<<endl;}

    };

    void main(void)

    {

    Base*pd=ne


    正确答案:Base:97。
    Base:97。 解析: 本题主要考查两个知识点,一是基类指针可以指向派生类对象,并可以访问派生类的所有成员。二是在函数重载中进行隐式类型转换。如pd->f(‘a’);系统到底调用哪个重载函数呢?实参既不是派生类中的形参,也不是基类中f函数的形参类型。此时系统根据就近原则和从高优先级到低优先级的规则尝试隐式转换。单字符更接近整数,故调用的是基类的f函数。

  • 第3题:

    类class one 在声明func 成员函数时发生错误,出错原因是【 】。

    Class one

    {

    private:

    int a;

    public:

    void func(two& )

    };

    class two

    {

    private:

    int b;

    friend void one: :func(two & );

    };

    void one: : func(two& r)

    a=r.b;

    }


    正确答案:class one前没有声明语句class two;
    class one前没有声明语句class two; 解析:当一个类作为另一个类的成员函数、成员函数的参数或其他情况的时候,要确保编译器能正确解析。由于在class one之前没有关于class two的任何说明,而在class one的func函数中却用了class two类的参数。因此是错误的。

  • 第4题:

    下列程序的运行结果是______。 include class Base { public: virtual void func(int

    下列程序的运行结果是______。

    include<iostream.h>

    class Base

    {

    public:

    virtual void func(int i){cout<<"class Base:"<<i<<end1;)

    };

    class Derived: public Base

    {

    public:

    void func(double d){cout<<"class Derived:"<<d<<endl;}

    };

    void main( )

    {

    Base a,*p=a;

    Derived b;

    p=&b;

    (*p).func(3.3);

    }


    正确答案:class Base:3
    class Base:3 解析:题中基类和派生类中有同名函数,但是参数不同。派生关系中,只有在函数类型、函数名和参数个数、参数类型完全相同时,才表现多态性。本题中参数不同,编译器便认为是两个完全不同的函数。通过基类的指针指向派生类对象时,该指针只能访问到派生类中具有多态性的成员函数,而与基类无关的函数是无法通过基类指针来访问的。故调用的是base类的 func函数,系统将3.3强制转化为整型数3。如果将派生类中的func的形参改为int型,则执行的就会是派生类的func函数,此时表现为多态。

  • 第5题:

    interface Data { public void load(); }  abstract class Info { public abstract void load(); }  Which class correctly uses the Data interface and Info class?() 

    • A、 public class Employee extends Info implements Data { public void load() { /*do something*/ } }
    • B、 public class Employee implements Info extends Data { public void load() { /*do something*/ } }
    • C、 public class Employee extends Info implements Data { public void load() { /*do something */ } public void Info.load() { /*do something*/ } }
    • D、 public class Employee implements Info extends Data { public void Data.load() { /*dsomething */ } public void load() { /*do something */ } }
    • E、 public class Employee implements Info extends Data { public void load() { /*do something */ } public void Info.load(){ /*do something*/ } }
    • F、 public class Employee extends Info implements Data{ public void Data.load() { /*do something*/ } public void Info.load() { /*do something*/ } }

    正确答案:A

  • 第6题:

    下面哪一个是正确的类的声明?()

    • A、public void HH{…}
    • B、public class Move(){…}
    • C、public class void number{}
    • D、public class Car{…}

    正确答案:D

  • 第7题:

    类Account中方法声明正确的是哪一项?()  

    • A、class Account{  deposit();  }
    • B、class Account{  void deposit(); }
    • C、class Account{  void deposit{}  }
    • D、class Account{  void deposit(){}  }

    正确答案:D

  • 第8题:

    单选题
    下面哪一个是正确的类的声明?()
    A

    public void HH{…}

    B

    public class Move(){…}

    C

    public class void number{}

    D

    public class Car{…}


    正确答案: D
    解析: 暂无解析

  • 第9题:

    单选题
    interface Data { public void load(); }  abstract class Info { public abstract void load(); }  Which class correctly uses the Data interface and Info class?()
    A

     public class Employee extends Info implements Data { public void load() { /*do something*/ } }

    B

     public class Employee implements Info extends Data { public void load() { /*do something*/ } }

    C

     public class Employee extends Info implements Data { public void load() { /*do something */ } public void Info.load() { /*do something*/ } }

    D

     public class Employee implements Info extends Data { public void Data.load() { /*dsomething */ } public void load() { /*do something */ } }

    E

     public class Employee implements Info extends Data { public void load() { /*do something */ } public void Info.load(){ /*do something*/ } }

    F

     public class Employee extends Info implements Data{ public void Data.load() { /*do something*/ } public void Info.load() { /*do something*/ } }


    正确答案: A
    解析: 暂无解析

  • 第10题:

    多选题
    Which two allow the class Thing to be instantiated using new Thing()?
    A

    public class Thing { }

    B

    public class Thing { public Thing() {} }

    C

    public class Thing { public Thing(void) {} }

    D

    public class Thing { public Thing(String s) {} }

    E

    public class Thing { public void Thing() {} public Thing(String s) {} }


    正确答案: E,A
    解析: 暂无解析

  • 第11题:

    单选题
    现有:  1. interface Animal {  2. void eat();  3. }  4.  5. // insert code here  6.  7. public class HouseCat extends Feline {  8. public void eat() { }  9. }   和五个声明:  abstract class Feline implements Animal { }  abstract class Feline implements Animal { void eat(); }  abstract class Feline implements Animal { public void eat(); }  abstract class Feline implements Animal { public void eat() { } }  abstract class Feline implements Animal { abstract public void eat(); }  分别插入到第5行,有几个可以通过编译?()
    A

    0

    B

    1

    C

    2

    D

    3


    正确答案: D
    解析: 暂无解析

  • 第12题:

    单选题
    现有:  interface Animal {       void eat () ;       }       //insert code here       public class HouseCat extends Feline {       public void eat() { }       }  和五个申明  abstract class Feline implements Animal { }  abstract  class  Feline  implements  Animal  {  void eat () ;  }  abstract class Feline implements Animal { public void eat();}  abstract class Feline implements Animal { public void eat() {}  }  abstract class Feline implements Animal { abstract public void eat();} 结果为:()
    A

    1

    B

    2

    C

    3

    D

    4


    正确答案: C
    解析: 暂无解析

  • 第13题:

    下列程序的运行结果是______。 include class A { public: virtual void use( ) {cou

    下列程序的运行结果是______。

    include<iostream.h>

    class A

    {

    public:

    virtual void use( ) {cout<<"in A\n";}

    };

    class B:public A

    {

    public:

    virtual void use( ) {cout<<"in B\n";}

    };

    class C:public B

    {

    public:

    virtual void use( ){cout<<"in C\n";}

    };

    void main( )

    {

    A*obj;

    bj=new C;

    obj->use( );

    delete obj;

    }


    正确答案:in C
    in C 解析:本题考查虚函数和多态性。原本obj指向祖先类,随后被赋值,指向新的子孙类,则在使用use这个重载的虚函数时,根据当前指向可确定调用子孙的同名虚函数。

  • 第14题:

    请写出下面的输出:

    class B

    {

    public:

    virtual void Print(void)

    {

    printf(“B::Print\n”);

    }

    virtual void Reprint(void)

    {

    printf(“B:Reprint\n”);

    }

    void Algo(void)

    {

    Print();

    Reprint();

    }

    };

    class D : public B

    {

    public:

    virtual void Print(void)

    {

    printf(“D::Print\n”);

    }

    };

    void main()

    {

    B *p = new D();

    p->Print();

    p->Algo();

    }


    正确答案:
     

  • 第15题:

    下列程序片段中,能通过编译的是( )。 A.public abstract class Animal{ public void speak;}S

    下列程序片段中,能通过编译的是( )。

    A.public abstract class Animal{ public void speak;}

    B.public abstract class Animal{ public void speak{);}

    C.public class Animal{ pubilc abstract void speak;}

    D.public abstract class Animal{ pubile abstract void speak{};}


    正确答案:A
    A。【解析】Java中一个类是一个abstract类的子类,它必须具体实现父类的abstract方法。如果一个类中含有abstract方法,那么这个类必须用abstract来修饰(abstract类也可以没有abstract方法)。有abstract方法的父类只声明,由继承它的子类实现。所以选A。

  • 第16题:

    class One {  void foo() {}  }  class Two extends One {   //insert method here  }  Which three methods, inserted individually at line 14, will correctly complete class Two?()

    • A、 int foo() { /* more code here */ }
    • B、 void foo() { /* more code here */ }
    • C、 public void foo() { /* more code here */ }
    • D、 private void foo() { /* more code here */ }
    • E、 protected void foo() { /* more code here */ }

    正确答案:B,C,E

  • 第17题:

    Which two allow the class Thing to be instantiated using new Thing()?

    • A、 public class Thing { }
    • B、 public class Thing { public Thing() {} }
    • C、 public class Thing { public Thing(void) {} }
    • D、 public class Thing { public Thing(String s) {} }
    • E、 public class Thing { public void Thing() {} public Thing(String s) {} }

    正确答案:A,B

  • 第18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19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?()  

    • 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:B

  • 第20题:

    单选题
    现有:  interface Data {public void load();}  abstract class Info {public abstract void load();}      下列类定义中正确使用Data和Info的是哪项?()
    A

     public class Employee implements Info extends Data { public void load(){/*dosomething*/}     }

    B

    public class Employee extends Inf.implements Data{ public void load() {/*do something*/}     }

    C

    public class Empl.yee implements Inf extends Data{ public void Data.1oad(){* do something*/}     public void load(){/*do something*/}     }

    D

    public class Employee extends Inf implements Data  {  public void Data.1oad()  {/*do something*/)     public void info.1oad(){/*do something*/}    }


    正确答案: D
    解析: 暂无解析

  • 第21题:

    多选题
    public abstract class Shape {  private int x;  private int y;  public abstract void draw();  public void setAnchor(int x, int y) {  this.x = x;  this.y = y;  }  }  Which two classes use the Shape class correctly?()
    A

    public class Circle implements Shape { private int radius; }

    B

    public abstract class Circle extends Shape { private int radius; }

    C

    public class Circle extends Shape { private int radius; public void draw(); }

    D

    public abstract class Circle implements Shape { private int radius; public void draw(); }

    E

    public class Circle extends Shape { private int radius;public void draw() {/* code here */} }

    F

    public abstract class Circle implements Shape { private int radius;public void draw() { / code here */ } }


    正确答案: B,E
    解析: 暂无解析

  • 第22题:

    单选题
    Given classes defined in two different files: 1.package util; 2.public class BitUtils{ 3.private static void process(byte[]b){} 4.} 1.package app; 2.public class SomeApp{ 3.public static void main(String[]args){ 4.byte[]bytes=newbyte[256]; 5.//insert code here 6.} 7.} What is required at line 5 in class SomeApp to use the process method of BitUtils?()
    A

    process(bytes);

    B

    BitUtils.process(bytes);

    C

    app.BitUtils.process(bytes);

    D

    util.BitUtils.process(bytes);

    E

    importutil.BitUtils.*;process(bytes);

    F

    SomeApp cannot use the process method in BitUtils.


    正确答案: B
    解析: 暂无解析

  • 第23题:

    单选题
    1.public class Test{ 2.int x=12; 3.public void method(intx){ 4.x+=x; 5.System.out.println(x); 6.} 7.} Given: 34.Test t=new Test(); 35.t.method(5); What is the output from line 5 of the Test class?()
    A

    5

    B

    10

    C

    12

    D

    17

    E

    24


    正确答案: D
    解析: 暂无解析