继承

继承重载方法事  修饰符作用域要大于或者等于原来的



class Father{
    private String name;
    private void p1(){
        System.out.println("父类似有方法");
    }
    private void p1(String a){
        System.out.println("父类似有方法"+a);
    }
    protected void test(){
        System.out.println("父类test");

    }
    
    protected void test(String a){
        System.out.println("父类test"+a);

    }
    protected void p2(){
        System.out.println("父类似有方法protect---p2");
    }
    public void question(){
        p1();
        p1("ttttt");
    }
}

class Son extends Father{
    
    private void p1(){
        
    }
    
    private void p1(String a){
        System.out.println("父类似有方法"+a);
    }
    
    public void test(){
        System.out.println("son-----test");
    }
    

    protected  void p2(){
        System.out.println("son-----有方法protect---p2");//重写方法是，访问权限只能变大或者与原来相等，私有方法不能被重写
    }


    public void p3(){
        System.out.println("son-----有方法public---p2");
    }
    

    
}
public class Extends1{

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Father f =new Father();
        f.test();
        f.p2();
        f.question();
        
        Father ff = new Son();//只能用父类对象指向子类
        ff.test();
        ff.p2();
        new Son().p3();
        
//        Son s = new Father();
//        s.test();  //这显然会报错
        
        
    }

}