四、super关键字

1.super关键字，用于成员变量super.age  用于调用父类的方法super.d()

public class Helloworld1 {
 public static void main(String args[]) {
  Cat c = new Cat("jacky",20);
  int m = c.m();
  System.out.println(m);
  }
 }
 class Animal {
  String name;
  int age = 10;
  public Animal(String name,int age) {
     this.name = name;
     this.age = age;
     }
     public void d() {
      System.out.println("....sleepping....");
      }
    }
  class Cat extends Animal {
   String name;
   int age = 20;
   public Cat(String name,int age) {
      super("aaa",10);
      }
     public int m() {
      super.d();
      return  super.age+age;
     }
   }

 

2.

super关键字，用于构造器，在继承中生成子类对象时，调用的是父类默认的无参构造方法，当父类的构造方法是有参时super("aaa",10)

public class Helloworld1 {
 public static void main(String args[]) {
    Cat c = new Cat("jacky",20);
  }
 }
 class Animal {
  String name;
  int age;
    public Animal(String name,int age) {
     this.name = name;
     this.age = age;
     }
    }
  class Cat extends Animal {
   String name;
   int age;
     public Cat(String name,int age) {
      super("aaa",10);
      }
   }