key; //Looping Through Object Properties: //For...in Loop for (const key in obj) { if (obj.hasOwnProperty(key)) { const value = obj[key]; // Do something with key and value } } //Object Methods //Object.keys() const keys = Object.keys(obj); //Object.values() const values...
Event Object Constant AT_TARGET BUBBLING_PHASE CAPTURING_PHASE Event Object Properties bubbles cancelable currentTarget eventPhase target timeStamp type Event Object Methods initEvent() preventDefault() stopPropagation() EventTarget Object addEventListener() ...
Errors –JS error handling. JSON –JavaScript Object Notation is syntax used for storing and exchanging data. Promises –The Promise object is used for asynchronous computation. See our example on how to declare one. Bookmark this JavaScript cheat sheet with Ctrl + D!HTML...
JavaScript Cheat SheetbyDaveChild JavaScript methods and functions, a guide to regular expressions and the XMLHttpRequest object. Regular Expressions Syntax ^ Start of string $ End of string . Any single character (a|b) a or b (...) ...
前端经常要通过 javaScript 来处理数组中的数据,其中就包括检查数组中是否包含满足特定搜索条件的单个或者多个值,这就需要我们关于用于确认的布尔值、数组中值得位置索引或包含所有搜索结果的单独数组等。 在ECMAScript6 之前,最常用的方法就是通过 for 循环来遍历数组中的所有项目并对项目执行操作。现在我们可以通过内置...
// Source file: src/types_advanced.js function makeObject<T1, T2>(x: T1, y: T2) { return { first: x, second: y }; } 还可以使用带有通用类型的参数化类型,稍后可以对其进行指定。在以下示例中,对于pair的类型定义允许您进一步创建新类型,每种类型将始终生成相同类型的值对: // Source file...
To use speak, we need to use the .bind, .call or .apply methods, which are available to all functions. The first parameter of these functions is the object which becomes this within the function. // bind creates a copy of the function it's being called on var cowSpeak = speak.bind...
Promise.all takes an array of promises as input and returns a promise object. The returned promise will be resolved when all the promises in the input array are resolved. If any of the promises in the input array is rejected, the returned promise will be rejected with the reason for the ...
Using ES6 Object Destructuring: const {foo, bar} = require('myfile.js');Per file, definemodule.exports(can be function, object, etc.) If you want to emulate ES6export default, just assign a single thing tomodule.exports, e.g.module.exports = function(){}; ...
The “for...in” loop is used to iterate over the properties of an object (a data structure that holds key-value pairs). It's particularly handy when you want to go through all the keys or properties of an object and perform an operation on each of them. ...