Object.getOwnPropertyNames(obj) IE9 返回一个包含了指定对象所有自有的属性名的数组(包含不可枚举的属性)。 该数组中枚举属性的顺序与通过 for...in loop(或 Object.keys)迭代该对象属性时一致,而数组中不可枚举属性的顺序未定义。 Object.getOwnPropertySymbols(obj) ES6 返回一个数组,它包含了指定对象自身所有...
letfs =require('fs')letevent = {// 发布与订阅没有关系_arr: [],on(fn) {this._arr.push(fn) },emit() {this._arr.forEach(fn=>fn()); } }letschool = {} event.on(function() {console.log("读取一个"); }) event.on(function() {if(Object.keys(school).length===2) {console....
> <video loop="true" ...> <video controls="false" ...> Note: The example with controls="false" can be a point of confusion for new developers - it will actually turn controls on! These are correct: <video controls ...> <video loop="loop" ...> <video ...> Player Readiness ...
那js单线程又是如何实现异步的呢 是通过事件循环(event loop)实现异步的,这个词在很多前端技术书籍上都提到过,但是每次看完,总是不理解,知道有那么一回事,但就是解释不清楚 下面这个经典的问题:猜猜它的输出结果 代码语言:javascript 代码运行次数:0 运行 AI代码解释 console.log('1')setTimeout(function(){con...
代码语言:javascript 代码运行次数:0 运行 复制 console.log(Object.keys(obj)); console.log(Object.values(obj)); //输出:["name", "career"] //输出:[ "Poly", "it"] 添加属性 代码语言:javascript 代码运行次数:0 运行 复制 //创建obj对象 var obj = new Object(); //为对象添加动态属性 obj....
var async; for (async of []); // SyntaxError: The left-hand side of a for-of loop may not be 'async'. UglifyJS may modify the input which in turn may suppress those errors. Some versions of Chrome and Node.js will give incorrect results with the following: console.log({ ...con...
loop Type:boolean Causes the video to start over as soon as it ends. muted Type:boolean Will silence any audio by default. poster Type:string A URL to an image that displays before the video begins playing. This is often a frame of the video or a custom title screen. As soon as the...
var async; for (async of []); // SyntaxError: The left-hand side of a for-of loop may not be 'async'. UglifyJS may modify the input which in turn may suppress those errors. Some versions of Chrome and Node.js will give incorrect results with the following: console.log({ ...con...
const keys = Object.keys(obj) return keys.reduce((memo, current) => { const value = obj[current] if (typeof value === 'object') { return { ...memo, [current]: deepClone(value), } } return { ...memo, [current]: value, ...
In custom filters, you can get values of other fields and perform validation based on that. You can also get any data from the context object, like request or user information, as it’s all provided in custom function callback parameters. ...