1.获取对象的隐式原型
Object.getPrototypeOf(对象) === 对象.__proto__
2.判断当前对象（this）是否在指定对象的原型链上
Object.prototype.isPrototypeOf(对象)
判断是不是真数组：
Array.prototype.isPrototypeOf([]);
Array.isArray([]);
3.判断函数的原型是否在对象的原型链上
对象 instanceof 函数（不推荐使用）
4.创建一个新对象，该新对象的隐式原型指向指定的对象
Object.create(对象)
var obj = Object.create(Object.prototype);
obj.__proto__ === Object.prototype
5.判断一个对象自身是否拥有某个属性
Object.prototype.hasOwnProperty(属性名);
for(var prop in obj){
if(obj.hasOwnProperty(prop)){//遍历属性的时候，不需要把原型链上的属性遍历
}
}
应用：
1.类数组转换为真数组
Array.prototype.slice.call(类数组);
[].slice.call(类数组);
2.实现继承
this.myPlugin = this.myPlugin || {}; /** * 子类继承父类实现方式一 */ this.myPlugin.inherit = function (son, father) { son.prototype = Object.create(father.prototype); son.prototype.constructor = son; son.prototype.uber = father.prototype; } /** * 子类继承父类实现方式二 */ this.myPlugin.inherit = (function (son, father) { var Temp = function () {}; return function (son, father) { Temp.prototype = father.prototype; son.prototype = new Temp(); son.prototype.constructor = son; son.prototype.uber = father.prototype; } }());
调用继承：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <body> <script src="./js/myPlugin.js"></script> <script> function User(firstName, lastName, age){ this.firstName = firstName; this.lastName = lastName; this.age = age; } User.prototype.sayHello = function(){ console.log(`我叫${this.firstName}${this.lastName}，今年${this.age}岁了`); } function VIPUser(firstName, lastName, age, money){ User.call(this, firstName, lastName, age); this.money = money; } //VIPUser继承自User myPlugin.inherit(VIPUser, User); VIPUser.prototype.recharge = function(money){ this.money += money; } var user = new User("李", "四", "19"); var vip = new VIPUser("张", "三", "18", "500"); vip.sayHello(); console.log(user); console.log(vip); </script> </body> </html>
效果展示：
