已定义类Aclass:class Aclass {private int x = 1;protected int y = 2;public int z = 3;public int sumA(){ return(x +y +z ); }}再通过继承与扩展定义子类Bclass:class Bclass extends Aclass {private
A: s += b;
B: s += x;
C: s += z;
D: s += y;
A: s += b;
B: s += x;
C: s += z;
D: s += y;
举一反三
- 有如下类定义:public class S extends F{S(int x){ }S(int x,int y) {super(x,y);}}则类F中一定有构造方法
- 现有两个类AClass、BClass,以下描述中表示BClass继承自AClass的是( )。 A: class AClass extends BClass B: class BClass implements AClass C: class AClass implements BClass D: class BClass extends AClass
- 中国大学MOOC: 定义类A如下:class A{ int a,b,c; public void B(int x,int y, int z){ a=x;b=y;c=z;}}
- 分析程序,将代码补充完整class A { private int x; public A(int i) { x = i; } } class B extends A { private int y; public B(int i) { ___________ ____; y = i; } }
- class A { public int f(int x,int y) { return x+y; } } class B extends A { public int f(byte x,int y) { return x*y; } } 子类B的对象只能调用子类中的f方法。( )