PhoneObject

package cn.yyhl.day15;

public class PhoneObject {
    public static void main(String[] args) {
        Phone phone = new Phone();
        phone.call();//打电话！
        phone.send();//发短信！
        phone.show();//显示号码！
        System.out.println("================");

        NewPhone phone1 = new NewPhone();
        phone1.call();//打电话！
        phone1.send();//发短信！
        phone1.show();//显示号码！显示姓名！显示头像！

    }
}

package cn.yyhl.day15;

public class Phone {
    public void call(){
        System.out.println("打电话！");
    }

    public void send(){
        System.out.println("发短信！");
    }

    public void show(){
        System.out.println("显示号码！");
    }
}

package cn.yyhl.day15;

public class NewPhone extends Phone {
    public void show(){
        super.show();
        System.out.println("显示姓名！");
        System.out.println("显示头像！");
    }
}