一些优秀的函数写法
查询链接中的参数：
function getQueryStringArgs() { //get query string without the initial ? var qs = (location.search.length > 0 ? location.search.substring(1) : ""), //object to hold data args = {}, //get individual items items = qs.length ? qs.split("&") : [], item = null, name = null, value = null, //used in for loop i = 0, len = items.length; //assign each item onto the args object for (i = 0; i < len; i++) { item = items[i].split("="); name = decodeURIComponent(item[0]); value = decodeURIComponent(item[1]); if (name.length) { args[name] = value; } } return args; } //assume query string of ?q=javascript&num=10 var args = getQueryStringArgs(); alert(args["name"]); //"javascript" alert(args["age"]); //"10"
检测所有浏览器插件方法（由于ie和其他浏览器检测区别很大，所以每个插件应用单独的方法比较好）
//plugin detection - doesn't work in IE function hasPlugin(name){ name = name.toLowerCase(); for (var i=0; i < navigator.plugins.length; i++){ if (navigator.plugins[i].name.toLowerCase().indexOf(name) > -1){ return true; } } return false; } //plugin detection for IE function hasIEPlugin(name){ try { new ActiveXObject(name); return true; } catch (ex){ return false; } } //detect flash for all browsers function hasFlash(){ var result = hasPlugin("Flash"); if (!result){ result = hasIEPlugin("ShockwaveFlash.ShockwaveFlash"); } return result; } //detect quicktime for all browsers function hasQuickTime(){ var result = hasPlugin("QuickTime"); if (!result){ result = hasIEPlugin("QuickTime.QuickTime"); } return result; } //detect flash alert(hasFlash()); //detect quicktime alert(hasQuickTime());
能力检测的基本模式：
if(object.propertyInQusetion){ // 使用object.propertyInQusetion }
更可靠的能力检测是检测他的类型（如下：利用typeof 更可靠）
function isHostMethod(object, porperty) { var t = typeof object[porperty]; return t == "function" || (!!(t == "object" && object[porperty])) || t == "unknown"; } var result = isHostMethod(xhr,'open'); //true var result1 = isHostMethod(xhr,'foo'); //false
完整的用户代理字符串检测脚本（包括检测呈现引擎、平台、windows操作系统、移动设备和游戏系统）
var client = function(){ //呈现引擎 var engine = { ie: 0, gecko: 0, webkit: 0, khtml: 0, opera: 0, //完整的版本号 ver: null }; //浏览器 var browser = { //主要浏览器 ie: 0, firefox: 0, safari: 0, konq: 0, opera: 0, chrome: 0, //具体的版本号 ver: null }; //平台、设备和操作系统 var system = { win: false, mac: false, x11: false, //移动设备 iphone: false, ipod: false, ipad: false, ios: false, android: false, nokiaN: false, winMobile: false, //游戏系统 wii: false, ps: false }; //检测呈现引擎和浏览器 var ua = navigator.userAgent; if (window.opera){ engine.ver = browser.ver = window.opera.version(); engine.opera = browser.opera = parseFloat(engine.ver); } else if (/AppleWebKit\/(\S+)/.test(ua)){ engine.ver = RegExp["$1"]; engine.webkit = parseFloat(engine.ver); //确定是 Chrome 还是 Safari if (/Chrome\/(\S+)/.test(ua)){ browser.ver = RegExp["$1"]; browser.chrome = parseFloat(browser.ver); } else if (/Version\/(\S+)/.test(ua)){ browser.ver = RegExp["$1"]; browser.safari = parseFloat(browser.ver); } else { //近似地确定版本号 var safariVersion = 1; if (engine.webkit < 100){ safariVersion = 1; } else if (engine.webkit < 312){ safariVersion = 1.2; } else if (engine.webkit < 412){ safariVersion = 1.3; } else { safariVersion = 2; } browser.safari = browser.ver = safariVersion; } } else if (/KHTML\/(\S+)/.test(ua) || /Konqueror\/([^;]+)/.test(ua)){ engine.ver = browser.ver = RegExp["$1"]; engine.khtml = browser.konq = parseFloat(engine.ver); } else if (/rv:([^\)]+)\) Gecko\/\d{8}/.test(ua)){ engine.ver = RegExp["$1"]; engine.gecko = parseFloat(engine.ver); //确定是不是 Firefox if (/Firefox\/(\S+)/.test(ua)){ browser.ver = RegExp["$1"]; browser.firefox = parseFloat(browser.ver); } } else if (/MSIE ([^;]+)/.test(ua)){ engine.ver = browser.ver = RegExp["$1"]; engine.ie = browser.ie = parseFloat(engine.ver); } //检测浏览器 browser.ie = engine.ie; browser.opera = engine.opera; //检测平台 var p = navigator.platform; system.win = p.indexOf("Win") == 0; system.mac = p.indexOf("Mac") == 0; system.x11 = (p == "X11") || (p.indexOf("Linux") == 0); //检测 windows 操作系统 if (system.win){ if (/Win(?:dows )?([^do]{2})\s?(\d+\.\d+)?/.test(ua)){ if (RegExp["$1"] == "NT"){ switch(RegExp["$2"]){ case "5.0": system.win = "2000"; break; case "5.1": system.win = "XP"; break; case "6.0": system.win = "Vista"; break; case "6.1": system.win = "7"; break; default: system.win = "NT"; break; } } else if (RegExp["$1"] == "9x"){ system.win = "ME"; } else { system.win = RegExp["$1"]; } } } //移动设备 system.iphone = ua.indexOf("iPhone") > -1; system.ipod = ua.indexOf("iPod") > -1; system.ipad = ua.indexOf("iPad") > -1; system.nokiaN = ua.indexOf("NokiaN") > -1; //windows mobile if (system.win == "CE"){ system.winMobile = system.win; } else if (system.win == "Ph"){ if(/Windows Phone OS (\d+.\d+)/.test(ua)){; system.win = "Phone"; system.winMobile = parseFloat(RegExp["$1"]); } } //检测 iOS 版本 if (system.mac && ua.indexOf("Mobile") > -1){ if (/CPU (?:iPhone )?OS (\d+_\d+)/.test(ua)){ system.ios = parseFloat(RegExp.$1.replace("_", ".")); } else { system.ios = 2; //can't really detect - so guess } } //检测 Android 版本 if (/Android (\d+\.\d+)/.test(ua)){ system.android = parseFloat(RegExp.$1); } //游戏系统 system.wii = ua.indexOf("Wii") > -1; system.ps = /playstation/i.test(ua); //返回这些对象 return { engine: engine, browser: browser, system: system }; }();
把nodeList转为数组（适合所有浏览器）：
function convertToArray(nodes){ var array = null; try{ array.prototype.slice.call(nodes,0);//针对非IE浏览器 }catch(ex){ array = new Array(); for(var i = 0,len = nodes.length;i<len;i++){ array.push(node[i]); } } return array; }
ie9+利用css选择器函数：
function matchesSelector(element, selector){ if (element.matchesSelector){ return element.matchesSelector(selector); } else if (element.msMatchesSelector){ return element.msMatchesSelector(selector); } else if (element.mozMatchesSelector){ return element.mozMatchesSelector(selector); } else if (element.webkitMatchesSelector){ return element.webkitMatchesSelector(selector); } else { throw new Error("Not supported."); } } if (matchesSelector(document.body, "body.page1")){ alert("It's page 1!"); }
