Java重写equals方法 Li.032

未重写前equals是比较引用的地址, 如比较2个对象, 地址一定是不同的

重写后, 可以比较对象的属性相同, 则认为对象相同

public class Demo1_Object {
    private int age;
    private String name;
    Demo1_Object(){}
    Demo1_Object(int age,String name){
        this.age  = age;
        this.name = name;
    }
    public static void main(String[] args) {
        Demo1_Object d  = new Demo1_Object(12, "xiaoming");
        Demo1_Object d2 = new Demo1_Object(12, "xiaohong");
        Demo1_Object d3 = new Demo1_Object(12, "xiaoming");
        System.out.println(d.equals(d2));
        System.out.println(d.equals(d3));
    }
    public boolean equals(Object obj){
        // 重写Object 类中equals方法
        if( obj instanceof Demo1_Object ){
            Demo1_Object demo = (Demo1_Object)obj;
            return this.name.equals(demo.name) && this.age == demo.age;
        }
        return false;
    }
    public boolean equals(Demo1_Object dobj){
        //这个不是重写, 是重载
        return this.name.equals(dobj.name) && this.age == dobj.age;
    }
    public String toString(){
        return (age + name);
    }
}