Java（14）：继承

package zzz;

// 创建继承

public class Demo2 {
    
    public static void main(String[] args) {
        
        Animal animal = new Animal();
        animal.live();
        animal.run();
        
        System.out.println("******************************************");
        
        Cat catAnimal = new Cat();
        catAnimal.live();
        catAnimal.run();
        
        System.out.println("******************************************");
        
        SmallCat smallCat = new SmallCat();
        smallCat.run();
        smallCat.live();
        
        System.out.println("******************************************");
        
        Dog dog = new Dog();
        dog.run();

    }
    
}


class Animal {
    
    String animal = "animal";
    
    public Animal() {
        System.out.println("父类构造函数Animal结束.");
    }
    public void live() {
        System.out.println(animal+" live ...");
    }
    public void run() {
        System.out.println(animal + " can run ...");
    }
}

class Dog extends Animal {
    String animal = "dog";
    
    public Dog() {
        System.out.println("Dog() end.");
    }
    @Override
    public void run() {
        System.out.println(super.animal + " can run, " + this.animal + " can run ...");
    }
}

class Cat extends Animal {

    String animal = "cat";
    
    public Cat() {
//        调用父类的构造函数
        super();
        System.out.println("子类构造函数Cat结束.");
    }

    @Override
    public void run() {
        System.out.println(super.animal + " can run, such as " + this.animal);
    }
    @Override
    public void live() {
//        子类调用父类的方法
        super.live();
    }
}

class SmallCat extends Cat {

    String animal = "small cat";
    
    public SmallCat() {
//        继承子类默认会调用父类的无参构造函数，隐式存在一个super();调用父类Cat类的构造函数
        System.out.println("子类构造函数SmallCat结束.");
    }
    @Override
    public void run() {
        System.out.println(this.animal + " can run .");
    }
    @Override
    public void live() {
        super.live();
    }
}