单选题Which line contains a constructor in this class definition?()   public class Counter { // (1)   int current, step;   public Counter(int startValue, int stepValue) { // (2)   set(startValue);   setStepValue(stepValue);  }   public int get() { return cur

题目
单选题
Which line contains a constructor in this class definition?()   public class Counter { // (1)   int current, step;   public Counter(int startValue, int stepValue) { // (2)   set(startValue);   setStepValue(stepValue);  }   public int get() { return current; } // (3)   public void set(int value) { current = value; } // (4)   public void setStepValue(int stepValue) { step = stepValue; } // (5)  }
A

Code marked with (1) is a constructor

B

Code marked with (2) is a constructor

C

Code marked with (3) is a constructor

D

Code marked with (4) is a constructor

E

Code marked with (5) is a Constructor


相似考题
更多“单选题Which line contains a constructor in this class definition?()   public class Counter { // (1)   int current, step;   public Counter(int startValue, int stepValue) { // (2)   set(startValue);   setStepValue(stepValue);  }   public int get() { return cur”相关问题
  • 第1题:

    有如下类声明: class MyBASE{ int k; public: void set(int n){k=n;} int get( )const{return k;} }; class MyDERIVED:protected MyBASE{ protected: intj; public: void set(int m,int n){MyBASE::set(m);j=n;} int get( )const{return MyBASE::get( )+j;} }; 则类MyDERIVED中保护的数据成员和成员函数的个数是

    A.4

    B.3

    C.2

    D.1


    正确答案:B
    解析:在保护派生的单继承中,基类的公有数据成员和成员函数在派生类中成为保护成员。

  • 第2题:

    下列程序的输出结果是______。 include using namespace std; class base { public: in

    下列程序的输出结果是______。

    include<iostream>

    using namespace std;

    class base

    {

    public:

    int n;

    base(int x){n=x;}

    virtual void set(int m){n=m;cout<<n<<'';}

    };

    class deriveA:public base

    {

    public:

    deriveA(int x):base(x){}

    void set(int m){n+=m;cout<<n<<'';}

    };

    class deriveB:public base

    {

    public:

    deriveB(int x):base(x){}

    void set(int m){n+=m;cout<<n<<'';}

    };

    int main( )

    {

    deriveA d1(1);

    deriveB.d2(3);

    base*pbase;

    pbase=&d1;

    pbase->set(1);

    pbase=&d2;

    pbase->set(2);

    return 0;

    }


    正确答案:25
    25 解析:本题考核虚函数的定义和调用。在C++中,一个基类指针(或引用)可以用来指向它的派生类对象,而且通过这样的指针(或引用)调用虚函数时,被调用的是该指针(或引用)实际所指向的对象类的那个重定义版本。题中基类成员函数set( )被定义成虚函数,而且其派生类 deriveA和deriveB都有函数set( )的重定义版本,所以通过指针pbase的两次调用分别调用的是派生类deriveA和deriveB中定义的版本,即输出25。

  • 第3题:

    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?() 

    • 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;

    正确答案:D

  • 第4题:

    Given:  1. public class Method Over {  2. public void set Var (int a, int b, float c) {  3. }  4. }   Which two overload the set Var method()?

    • A、 private void set Var(int a, float c, int b) {}
    • B、 protected void set Var(int a, int b, float c) {}
    • C、 public int set Var(int a, float c, int b) {return a:}
    • D、 public int set Var(int a, int b, float c) {return a:}
    • E、 protected float set Var(int a, int b, float c) {return c:}

    正确答案:A,C

  • 第5题:

    10. interface Foo { int bar(); }  11. public class Sprite {  12. public int fubar( Foo foo) { return foo.bar(); }  13. public void testFoo() {  14. fubar(  15. // insert code here  16.);  17. }  18. }  Which code, inserted at line 15, allows the class Sprite to compile?() 

    • A、 Foo { public int bar() { return 1; } }
    • B、 new Foo { public int bar() { return 1; } }
    • C、 newFoo() { public int bar(){return 1; } }
    • D、 new class Foo { public int bar() { return 1; } }

    正确答案:C

  • 第6题:

    public class ConstOver {  public ConstOver (int x, int y, int z)  {  }  }   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、 Public void ConstOver (byte x, byte y, byte z) { }

    正确答案:A,C

  • 第7题:

    1) class Person {  2) public void printValue(int i, int j) {/*…*/ }     3) public void printValue(int i){/*...*/ }     4) }  5) public class Teacher extends Person {     6) public void printValue() {/*...*/ }     7) public void printValue(int i) {/*...*/}     8) public static void main(String args[]){     9) Person t = new Teacher();     10) t.printValue(10);     11) }    12) }  Which method will the statement on line 10 call? ()  

    • A、 on line 2
    • B、 on line 3
    • C、 on line 6
    • D、 on line 7

    正确答案:D

  • 第8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

  • 第9题:

    多选题
    1. class Super {  2. private int a;  3. protected Super(int a) { this.a = a; }  4. }  .....  11. class Sub extends Super {  12. public Sub(int a) { super(a); }  13. public Sub() { this.a= 5; }  14. }  Which two, independently, will allow Sub to compile?()
    A

    Change line 2 to: public int a;

    B

    Change line 2 to: protected int a;

    C

    Change line 13 to: public Sub() { this(5); }

    D

    Change line 13 to: public Sub() { super(5); }

    E

    Change line 13 to: public Sub() { super(a); }


    正确答案: C,B
    解析: 暂无解析

  • 第10题:

    单选题
    class A {   public int getNumber(int a) {   return a + 1;   }   }    class B extends A {   public int getNumber (int a) {   return a + 2   }    public static void main (String args) {   A a = new B();   System.out.printIn(a.getNumber(0));   }   }   What is the result? ()
    A

     Compilation succeeds and 1 is printed.

    B

     Compilation succeeds and 2 is printed.

    C

     An error at line 8 causes compilation to fail.

    D

     An error at line 13 causes compilation to fail.

    E

     An error at line 14 causes compilation to fail.


    正确答案: C
    解析: 暂无解析

  • 第11题:

    单选题
    10. interface Foo { int bar(); }  11. public class Sprite {  12. public int fubar( Foo foo) { return foo.bar(); }  13. public void testFoo() {  14. fubar(  15. // insert code here  16.);  17. }  18. }  Which code, inserted at line 15, allows the class Sprite to compile?()
    A

     Foo { public int bar() { return 1; } }

    B

     new Foo { public int bar() { return 1; } }

    C

     newFoo() { public int bar(){return 1; } }

    D

     new class Foo { public int bar() { return 1; } }


    正确答案: D
    解析: 暂无解析

  • 第12题:

    单选题
    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?()
    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;


    正确答案: C
    解析: 暂无解析

  • 第13题:

    有以下程序:include using namespace std;class A{private: int x,y;public: void se

    有以下程序: #include <iostream> using namespace std; class A { private: int x,y; public: void set (int i,int j) { x=i; y=j; } int get_y() { return y; } }; class box { private: int length,width; A label; public: void set(int 1,int w, int s,int p) { length=1; width=w; label.set(s,p); } int get_area() { return length*width; } }; int main() { box small; small.set(2,4,1,35); cout<<small.get_area()<<end1; return 0; } 运行后的输出结果是( )。

    A.8

    B.4

    C.35

    D.70


    正确答案:A
    解析:本题考核成员对象的应用。类box的成员函数set()为设置对象的坐标值和对象的长、宽值。成员函数setarea返回该对象的面积。程序最后输出为8。

  • 第14题:

    class A {  protected int method1(int a, int b) { return 0; }  }  Which two are valid in a class that extends class A?() 

    • A、 public int method1(int a, int b) { return 0; }
    • B、 private int method1(int a, int b) { return 0; }
    • C、 private int method1(int a, long b) { return 0; }
    • D、 public short method1(int a, int b) { return 0: }
    • E、 static protected int method1(int a, int b) { return 0; }

    正确答案:A,C

  • 第15题:

    Which line contains a constructor in this class definition?()   public class Counter { // (1)   int current, step;   public Counter(int startValue, int stepValue) { // (2)   set(startValue);   setStepValue(stepValue);  }   public int get() { return current; } // (3)   public void set(int value) { current = value; } // (4)   public void setStepValue(int stepValue) { step = stepValue; } // (5)  }  

    • A、Code marked with (1) is a constructor
    • B、Code marked with (2) is a constructor
    • C、Code marked with (3) is a constructor
    • D、Code marked with (4) is a constructor
    • E、Code marked with (5) is a Constructor

    正确答案:B

  • 第16题:

    1. class Super {  2. private int a;  3. protected Super(int a) { this.a = a; }  4. }  .....  11. class Sub extends Super {  12. public Sub(int a) { super(a); }  13. public Sub() { this.a= 5; }  14. }  Which two, independently, will allow Sub to compile?()

    • A、 Change line 2 to: public int a;
    • B、 Change line 2 to: protected int a;
    • C、 Change line 13 to: public Sub() { this(5); }
    • D、 Change line 13 to: public Sub() { super(5); }
    • E、 Change line 13 to: public Sub() { super(a); }

    正确答案:C,D

  • 第17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 “<“ + wins + “,“ + losses + “>”; }  // 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

  • 第18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19题:

    public class Parent {  public int addValue( int a, int b) {     int s;     s = a+b;     return s;     }     }  class Child extends Parent {  }  Which methods can be added into class Child?()   

    • A、 int addValue( int a, int b ){// do something...}
    • B、 public void addValue (){// do something...}
    • C、 public int addValue( int a ){// do something...}
    • D、 public int addValue( int a, int b )throws MyException {//do something...}

    正确答案:B,C

  • 第20题:

    单选题
    1) class Person {  2) public void printValue(int i, int j) {/*…*/ }     3) public void printValue(int i){/*...*/ }     4) }  5) public class Teacher extends Person {     6) public void printValue() {/*...*/ }     7) public void printValue(int i) {/*...*/}     8) public static void main(String args[]){     9) Person t = new Teacher();     10) t.printValue(10);     11) }    12) }  Which method will the statement on line 10 call? ()
    A

     on line 2

    B

     on line 3

    C

     on line 6

    D

     on line 7


    正确答案: D
    解析: 变量t是一个Person对象,但是它是用Teacher实例化的,这个问题涉及到java的编译时多态和运行时多态的问题,就编译时多态来说,t实际上是一个Person类,这涉及到类型的自动转换(将一个子类的实例赋值给一个父类的变量是不用进行强制类型转换,反之则需要 
    进行强制类型转换,而且被赋值的变量实际上应该是一个子类的对象),如果对t调用了子类中新增的方法则造成编译时错误编译将不能通过,而在运行时,运行时系统将根据t实际指向的类型调用对应的方法,对于本例来说,t.print(10)将调用t实际指向的Teacher类的对应方法。在java中,可以用一个子类的实例实例化父类的一个变量,而变量在编译时是一个父类实例,在运行时可能是一个子类实例。

  • 第21题:

    单选题
    Which line contains a constructor in this class definition?()   public class Counter { // (1)   int current, step;   public Counter(int startValue, int stepValue) { // (2)   set(startValue);   setStepValue(stepValue);  }   public int get() { return current; } // (3)   public void set(int value) { current = value; } // (4)   public void setStepValue(int stepValue) { step = stepValue; } // (5)  }
    A

    Code marked with (1) is a constructor

    B

    Code marked with (2) is a constructor

    C

    Code marked with (3) is a constructor

    D

    Code marked with (4) is a constructor

    E

    Code marked with (5) is a Constructor


    正确答案: E
    解析: 暂无解析

  • 第22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23题:

    多选题
    Given:  1. public class Method Over {  2. public void set Var (int a, int b, float c) {  3. }  4. }   Which two overload the set Var method()?
    A

    private void set Var(int a, float c, int b) {}

    B

    protected void set Var(int a, int b, float c) {}

    C

    public int set Var(int a, float c, int b) {return a:}

    D

    public int set Var(int a, int b, float c) {return a:}

    E

    protected float set Var(int a, int b, float c) {return c:}


    正确答案: A,C
    解析: 暂无解析

  • 第24题:

    单选题
    public class SyncTest {  private int x;   private int y;   public synchronized void setX (int i) (x=1;)   public synchronized void setY (int i) (y=1;)   public synchronized void setXY(int 1)(set X(i); setY(i);)   public synchronized Boolean check() (return x !=y;)   }   Under which conditions will check () return true when called from a different class?
    A

     Check() can never return true.

    B

     Check() can return true when setXY is called by multiple threads.

    C

     Check() can return true when multiple threads call setX and setY separately.

    D

     Check() can only return true if SyncTest is changed to allow x and y to be set separately.


    正确答案: D
    解析: 暂无解析