前端开发常用代码（分享一些实用的JS代码片段）

作者：小明来源：IT技术分享社区Function getBrowser() { var UserAgent = navigator.userAgent.toLowerCase(); var browserInfo = {}; var browserArray = { IE: window.ActiveXObject || "ActiveXObject" in window, // IE Chrome: UserAgent.indexOf('Chrome') > -1 && UserAgent.indexOf('safari') > -1, // Chrome浏览器 Firefox: UserAgent.indexOf('firefox') > -1, // 火狐浏览器 Opera: UserAgent.indexOf('opera') > -1, // Opera浏览器 Safari: UserAgent.indexOf('safari') > -1 && UserAgent.indexOf('chrome') == -1, // safari浏览器 Edge: UserAgent.indexOf('edge') > -1, // Edge浏览器 QQBrowser: /qqbrowser/.test(UserAgent), // qq浏览器 WeixinBrowser: /MicroMessenger/i.test(UserAgent) // 微信浏览器 }; // console.log(browserArray) for (var i in browserArray) { if (browserArray[i]) { var versions = ''; if (i == 'IE') { versions = UserAgent.match(/(msie\s|trident.*rv:)([\w.] )/)[2]; } else if (i == 'Chrome') { for (var mt in navigator.mimeTypes) { //检测是否是360浏览器(测试只有pc端的360才起作用) if (navigator.mimeTypes[mt]['type'] == 'application/360softmgrplugin') { i = '360'; } } versions = UserAgent.match(/chrome\/([\d.] )/)[1]; } else if (i == 'Firefox') { versions = UserAgent.match(/firefox\/([\d.] )/)[1]; } else if (i == 'Opera') { versions = UserAgent.match(/opera\/([\d.] )/)[1]; } else if (i == 'Safari') { versions = UserAgent.match(/version\/([\d.] )/)[1]; } else if (i == 'Edge') { versions = UserAgent.match(/edge\/([\d.] )/)[1]; } else if (i == 'QQBrowser') { versions = UserAgent.match(/qqbrowser\/([\d.] )/)[1]; } browserInfo.type = i; browserInfo.versions = parseInt(versions); } } return browserInfo; } ，下面我们就来说一说关于前端开发常用代码?我们一起去了解并探讨一下这个问题吧!

前端开发常用代码

作者：小明来源：IT技术分享社区

Function getBrowser() { var UserAgent = navigator.userAgent.toLowerCase(); var browserInfo = {}; var browserArray = { IE: window.ActiveXObject || "ActiveXObject" in window, // IE Chrome: UserAgent.indexOf('Chrome') > -1 && UserAgent.indexOf('safari') > -1, // Chrome浏览器 Firefox: UserAgent.indexOf('firefox') > -1, // 火狐浏览器 Opera: UserAgent.indexOf('opera') > -1, // Opera浏览器 Safari: UserAgent.indexOf('safari') > -1 && UserAgent.indexOf('chrome') == -1, // safari浏览器 Edge: UserAgent.indexOf('edge') > -1, // Edge浏览器 QQBrowser: /qqbrowser/.test(UserAgent), // qq浏览器 WeixinBrowser: /MicroMessenger/i.test(UserAgent) // 微信浏览器 }; // console.log(browserArray) for (var i in browserArray) { if (browserArray[i]) { var versions = ''; if (i == 'IE') { versions = UserAgent.match(/(msie\s|trident.*rv:)([\w.] )/)[2]; } else if (i == 'Chrome') { for (var mt in navigator.mimeTypes) { //检测是否是360浏览器(测试只有pc端的360才起作用) if (navigator.mimeTypes[mt]['type'] == 'application/360softmgrplugin') { i = '360'; } } versions = UserAgent.match(/chrome\/([\d.] )/)[1]; } else if (i == 'Firefox') { versions = UserAgent.match(/firefox\/([\d.] )/)[1]; } else if (i == 'Opera') { versions = UserAgent.match(/opera\/([\d.] )/)[1]; } else if (i == 'Safari') { versions = UserAgent.match(/version\/([\d.] )/)[1]; } else if (i == 'Edge') { versions = UserAgent.match(/edge\/([\d.] )/)[1]; } else if (i == 'QQBrowser') { versions = UserAgent.match(/qqbrowser\/([\d.] )/)[1]; } browserInfo.type = i; browserInfo.versions = parseInt(versions); } } return browserInfo; }

function colorRGBtoHex(color) { var rgb = color.split(','); var r = parseInt(rgb[0].split('(')[1]); var g = parseInt(rgb[1]); var b = parseInt(rgb[2].split(')')[0]); var hex = "#" ((1 << 24) (r << 16) (g << 8) b).toString(16).slice(1); return hex; }

< script type = "text/javascript" > //屏蔽右键菜单 document.oncontextmenu = function(event) { if (window.event) { event = window.event; } try { var the = event.srcElement; if (! ((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) { return false; } return true; } catch(e) { return false; } } //屏蔽粘贴 document.onpaste = function(event) { if (window.event) { event = window.event; } try { var the = event.srcElement; if (! ((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) { return false; } return true; } catch(e) { return false; } } //屏蔽复制 document.oncopy = function(event) { if (window.event) { event = window.event; } try { var the = event.srcElement; if (! ((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) { return false; } return true; } catch(e) { return false; } } //屏蔽剪切 document.oncut = function(event) { if (window.event) { event = window.event; } try { var the = event.srcElement; if (! ((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) { return false; } return true; } catch(e) { return false; } } //屏蔽选中 document.onselectstart = function(event) { if (window.event) { event = window.event; } try { var the = event.srcElement; if (! ((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) { return false; } return true; } catch(e) { return false; } } < /script>/

function CheckDateTime(str){ var reg = /^(\d )-(\d{1,2})-(\d{1,2}) (\d{1,2}):(\d{1,2}):(\d{1,2})$/; var r = str.match(reg); if(r==null)return false; r[2]=r[2]-1; var d= new Date(r[1], r[2],r[3], r[4],r[5], r[6]); if(d.getFullYear()!=r[1])return false; if(d.getMonth()!=r[2])return false; if(d.getDate()!=r[3])return false; if(d.getHours()!=r[4])return false; if(d.getMinutes()!=r[5])return false; if(d.getSeconds()!=r[6])return false; return true; }

/** * 方法一：js字符串切割 * @param {*} str */ function firstToUpper1(str) { return str.trim().toLowerCase().replace(str[0], str[0].toUpperCase()); } /** * 方法二：js正则 * @param {*} str */ function firstToUpper2(str){ return str.replace(/\b(\w)(\w*)/g, function($0, $1, $2) { return $1.toUpperCase() $2.toLowerCase(); }); } /** * 方法三：js正则 * @param {*} str */ function firstToUpper3(str){ return str.toLowerCase().replace(/( |^)[a-z]/g,(L)=>L.toUpperCase()); }

function getDays(strDateStart,strDateEnd){ var strSeparator = "-"; //日期分隔符 var oDate1; var oDate2; var iDays; oDate1= strDateStart.split(strSeparator); oDate2= strDateEnd.split(strSeparator); var strDateS = new Date(oDate1[0], oDate1[1]-1, oDate1[2]); var strDateE = new Date(oDate2[0], oDate2[1]-1, oDate2[2]); iDays = parseInt(Math.abs(strDateS - strDateE ) / 1000 / 60 / 60 /24)//把相差的毫秒数转换为天数 return iDays ; }

function randomHexColor() { //随机生成十六进制颜色 var hex = Math.floor(Math.random() * 16777216).toString(16); //生成ffffff以内16进制数 while (hex.length < 6) { //while循环判断hex位数，少于6位前面加0凑够6位 hex = '0' hex; } return '#' hex; //返回‘#'开头16进制颜色 }

const removeDuplicates = (arr) => [...new Set(arr)]; console.log(removeDuplicates([1, 2, 3, 3, 4, 4, 5, 5, 6])); // Result: [ 1, 2, 3, 4, 5, 6 ]

function getParameterByName(name, url) { if (!url) url = window.location.href; name = name.replace(/[\[\]]/g, "\\$&"); var regex = new RegExp("[?&]" name "(=([^&#]*)|&|#|$)"), results = regex.exec(url); if (!results) return null; if (!results[2]) return ''; return decodeURIComponent(results[2].replace(/\ /g, " ")); }

const isEven = num => num % 2 === 0; console.log(isEven(2)); // Result: True

const average = (...args) => args.reduce((a, b) => a b) / args.length; average(1, 2, 3, 4); // Result: 2.5

function topFunction() { document.body.scrollTop = 0; document.documentElement.scrollTop = 0; }

// reverse var name = "My city is WH"; var resultStr = name.split('').reverse().join(''); console.log(resultStr); // HW si ytic yM// charAt var name = "My city is WuHan"; var nameArr = name.split(''); var resultStr = ''; for (var i = nameArr.length-1; i >= 0; i--) { resultStr = name.charAt(i); } console.log(resultStr); // naHuW si ytic yM

const isNotEmpty = arr => Array.isArray(arr) && arr.length > 0; isNotEmpty([1, 2, 3]); // Result: true