classb.java

java课件及例程有一些PPT及一些例程

class SuperA{
    //域定义
    public int x1=4;
    protected int x2=5;
    private int x3=6;
    //方法定义
    public void add_x1(int a){
    	x1+=a;
    }
    public void add_x2(int a){
    	x2+=a;
    }
    public void add_x3(int a){
    	x3+=a;
    }
    public int get_x3(){
    	return x3;
    }
    public void set_x3(int a){
        x3=a;
    }

}

class ClassB extends SuperA{
    public void sub_x1(int a){
    	x1-=a;
    }
    public void sub_x2(int a){
    	x2-=a;
    }
    public void sub_x3(int a){
    	int i=0;
    	i = get_x3();
    	i-=a;
    	set_x3(i);
    }

    public static void main(String[] args){
        int a =2;
        SuperA aa=new SuperA();
        System.out.println("初值：aa.x1="+aa.x1+", aa.x2="+aa.x2+", aa.x3="+aa.get_x3());
        aa.add_x1(a);
        aa.add_x2(a);
        aa.add_x3(a);
        System.out.println("调用方法后：aa.x1="+aa.x1+", aa.x2="+aa.x2+", aa.x3="+aa.get_x3());
        ClassB bb=new ClassB();
        System.out.println("初值：bb.x1="+bb.x1+", bb.x2="+bb.x2+", bb.x3="+bb.get_x3());
        bb.add_x1(a);
        bb.add_x2(a);
        bb.add_x3(a);
        System.out.println("调用add方法后：bb.x1="+bb.x1+", bb.x2="+bb.x2+", bb.x3="+bb.get_x3());
        bb.sub_x1(a);
        bb.sub_x2(a);
        bb.sub_x3(a);
        System.out.println("调用sub方法后：bb.x1="+bb.x1+", bb.x2="+bb.x2+", bb.x3="+bb.get_x3());    
    }
}