Class Puppy

HelloWorld.java:8–21

 }

public class Puppy{
    public Puppy(){
        name = "大黄";
    }

    public Puppy(String name){
        // 这个构造器仅有一个参数：name
        this.name = name;
    }
    public Puppy(String name, int age){
        // 这个构造器仅有一个参数：name
        this.name = name;
    }
}

da_huang = Puppy();
da_huang = Puppy("大红");