JavaScript的API

"use strict"
var obj1 = new Object();
var obj2 = new Object();
//此处为obj1添加的name属性即为实例属性
obj1.name = "Tom";
console.log(obj1.hasOwnProperty("name"));//true
console.log(obj2.hasOwnProperty("name"));//false
delete obj1.name;
console.log(obj1.hasOwnProperty("name"));//false

"use strict"
var obj1 = {};
var obj2 = {};
//在Object函数的原型对象中添加job属性（一般不会在Object函数的原型对象中添加属性，此处只是为了演示）
Object.prototype.job = "software engineer";
obj1.job = "hardware engineer";
console.log(obj1.hasOwnProperty("job"));//true
console.log("job" in obj1);//true
console.log(obj2.hasOwnProperty("job"));//false
console.log("job" in obj2);//true
console.log("***********")
//在实例中添加的属性会屏蔽掉原型中的同名属性
console.log(obj1.job);//hardware engineer