在网站建设开发中,我们有时需要知道对象的所有属性,原生js给我们提供了一个很好的方法:Object.keys(),该方法返回一个数组传入对象,返回属性名:
var obj = {'a':'123','b':'345'}; console.log(Object.keys(obj)); //['a','b'] var obj1 = { 100: "a", 2: "b", 7: "c"}; console.log(Object.keys(obj1)); // console: ["2", "7", "100"] var obj2 = Object.create({}, { getFoo : { value : function () { return this.foo } } }); obj2.foo = 1; console.log(Object.keys(obj2)); // console: ["foo"]
传入字符串,返回索引
var str = 'ab1234'; console.log(Object.keys(obj)); //[0,1,2,3,4,5]
构造函数 返回空数组或者属性名
function Pasta(name, age, gender) { this.name = name; this.age = age; this.gender = gender; this.toString = function () { return (this.name + ", " + this.age + ", " + this.gender); } } console.log(Object.keys(Pasta)); //console: [] var spaghetti = new Pasta("Tom", 20, "male"); console.log(Object.keys(spaghetti)); //console: ["name", "age", "gender", "toString"]
数组 返回索引
var arr = ["a", "b", "c"]; console.log(Object.keys(arr)); // console: ["0", "1", "2"]
好了,今天和大家分享的Object.keys方法实例详解就是这些内容,你看完后喜欢的话记得收藏哦。
地址:绵阳市临园路东段78号B座13层
电话:0816-6339181
邮箱:kf@kf51.cn
微信公众号:
Copyright © 绵阳动力网站建设 www.kf51.cn All Rights Reserved 蜀ICP备08100083号