对于过滤器函数本身,我已经实现了 MDN 文档 底部描述的 polyfill:if (!Array.prototype.filter) Array.prototype.filter = function(func, thisArg) { 'use strict'; if ( ! ((typeof func === 'Function') && this) ) throw new TypeError(); var len = this.length >>> 0, res = new Array(len...
var newArray = array.filter(function(item) { return condition; }); CopyThe item argument is a reference to the current element in the array as filter() checks it against the condition. This is useful for accessing properties, in the case of objects....
Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on iOS Samsung Internet WebView Android WebView on iOS Deno Node.js filter Legend Tip: you can click/tap on a cell for more information. Full support Full support...
varnames=['Alice','Bob','Tiff','Bruce','Alice'];varcountedNames=names.reduce(function(allNames,name){if(nameinallNames){allNames[name]++;}else{allNames[name]=1;}returnallNames;},{});// countedNames is:// { 'Alice': 2, 'Bob': 1, 'Tiff': 1, 'Bruce': 1 } 3.5 按属性对ob...
我们首先来看一看 MDN 上对 Map 和 ForEach 的定义: forEach(): 针对每一个元素执行提供的函数(executes a provided function once for each array element)。 map(): 创建一个新的数组,其中每一个元素由调用数组中的每一个元素执行提供的函数得来(creates a new array with the results of calling a provi...
一.forEach、for in、for of三者区别1)forEachforEach用来遍历数组,不能中断循环(使用break和return)var arr=["a","b","c","d"] arr.forEach(function(val,index,arr){ //val当前元素 index当前元素的索引 arr数组 console.log(val,in es6的filter使用 ...
代码语言:javascript 代码运行次数:0 复制 Array.prototype.filter=function(callbackfn,thisArg){// 处理数组类型异常if(this===null||this===undefined){thrownewTypeError("Cannot read property 'filter' of null or undefined");}// 处理回调类型异常if(Object.prototype.toString.call(callbackfn)!="[object...
同一个MDN页面上的polyfill表示的算法与ECMA-262第五版中指定的算法完全相同。
一.forEach、for in、for of三者区别1)forEachforEach用来遍历数组,不能中断循环(使用break和return)var arr=["a","b","c","d"] arr.forEach(function(val,index,arr){ //val当前元素 index当前元素的索引 arr数组 console.log(val,in es6的filter使用 ...
According to MDN documentation: The filter() method creates a new array with all elements that pass the test implemented by the provided function. Let us simplify this further by using an example. If you have an array of random numbers (e.g ages of people) and you only need numbers that...