82个常规的前端JavaScript方法封装(31~40)
发表于:2021-12-05 17:22:47浏览:2132次
本篇文章主要介绍的是一些常用的前端JavaScript方法封装,数组排序,遍历Dom树,原生js封装ajax,异步加载script,cookie管理等,自己收集整理以便后期使用,需要的朋友可以阅读收藏。
31、数组排序
// 快排 [left] + min + [right] function quickArr(arr) { if (arr.length <= 1) { return arr; } var left = [], right = []; var pIndex = Math.floor(arr.length / 2); var p = arr.splice(pIndex, 1)[0]; for (var i = 0; i < arr.length; i++) { if (arr[i] <= p) { left.push(arr[i]); } else { right.push(arr[i]); } } // 递归 return quickArr(left).concat([p], quickArr(right)); } // 冒泡 function bubbleSort(arr) { for (var i = 0; i < arr.length - 1; i++) { for (var j = i + 1; j < arr.length; j++) { if (arr[i] > arr[j]) { var temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } } } return arr; } function bubbleSort(arr) { var len = arr.length; for (var i = 0; i < len - 1; i++) { for (var j = 0; j < len - 1 - i; j++) { if (arr[j] > arr[j + 1]) { var temp = arr[j]; arr[j] = arr[j + 1]; arr[j + 1] = temp; } } } return arr; }
32、遍历Dom树
// 给定页面上的DOM元素,将访问元素本身及其所有后代(不仅仅是它的直接子元素) // 对于每个访问的元素,函数讲元素传递给提供的回调函数 function traverse(element, callback) { callback(element); var list = element.children; for (var i = 0; i < list.length; i++) { traverse(list[i], callback); } }
33、原生js封装ajax
function ajax(method, url, callback, data, flag) { var xhr; flag = flag || true; method = method.toUpperCase(); if (window.XMLHttpRequest) { xhr = new XMLHttpRequest(); } else { xhr = new ActiveXObject('Microsoft.XMLHttp'); } xhr.onreadystatechange = function () { if (xhr.readyState == 4 && xhr.status == 200) { console.log(2) callback(xhr.responseText); } } if (method == 'GET') { var date = new Date(), timer = date.getTime(); xhr.open('GET', url + '?' + data + '&timer' + timer, flag); xhr.send() } else if (method == 'POST') { xhr.open('POST', url, flag); xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); xhr.send(data); } }
34、异步加载script
function loadScript(url, callback) { var oscript = document.createElement('script'); if (oscript.readyState) { // ie8及以下版本 oscript.onreadystatechange = function () { if (oscript.readyState === 'complete' || oscript.readyState === 'loaded') { callback(); } } } else { oscript.onload = function () { callback() }; } oscript.src = url; document.body.appendChild(oscript); }
35、cookie管理
var cookie = { set: function (name, value, time) { document.cookie = name + '=' + value + '; max-age=' + time; return this; }, remove: function (name) { return this.setCookie(name, '', -1); }, get: function (name, callback) { var allCookieArr = document.cookie.split('; '); for (var i = 0; i < allCookieArr.length; i++) { var itemCookieArr = allCookieArr[i].split('='); if (itemCookieArr[0] === name) { return itemCookieArr[1] } } return undefined; } }
36、实现bind()方法
Function.prototype.myBind = function (target) { var target = target || window; var _args1 = [].slice.call(arguments, 1); var self = this; var temp = function () {}; var F = function () { var _args2 = [].slice.call(arguments, 0); var parasArr = _args1.concat(_args2); return self.apply(this instanceof temp ? this : target, parasArr) } temp.prototype = self.prototype; F.prototype = new temp(); return F; }
37、实现call()方法
Function.prototype.myCall = function () { var ctx = arguments[0] || window; ctx.fn = this; var args = []; for (var i = 1; i < arguments.length; i++) { args.push(arguments[i]) } var result = ctx.fn(...args); delete ctx.fn; return result; }
38、实现apply()方法
Function.prototype.myApply = function () { var ctx = arguments[0] || window; ctx.fn = this; if (!arguments[1]) { var result = ctx.fn(); delete ctx.fn; return result; } var result = ctx.fn(...arguments[1]); delete ctx.fn; return result; }
39、防抖
function debounce(handle, delay) { var timer = null; return function () { var _self = this, _args = arguments; clearTimeout(timer); timer = setTimeout(function () { handle.apply(_self, _args) }, delay) } }
40、节流
function throttle(handler, wait) { var lastTime = 0; return function (e) { var nowTime = new Date().getTime(); if (nowTime - lastTime > wait) { handler.apply(this, arguments); lastTime = nowTime; } } }