function Animal(name, color) {
    this.name = name
    this.color = color
    Animal.prototype.sleep = function () {
        console.log("动物在睡觉")
    }
}

// 实例化一个动物实体
var pro_animal = new Animal()
// 让狗的构造指向这个实体
Dog.prototype = pro_animal
// 让狗原型指向狗构造
pro_animal.constructor = Dog


function Dog(name, color) {
    // 借用父类构造方法来实现属性的继承
    Animal.call(this, name, color)
    Dog.prototype.gard = function () {
        console.log("狗在看家")
    }
}

var wc = new Dog("旺财", "黄色")
wc.sleep()
wc.gard()