JavaScript实用功能代码片段整理二

31、原生JavaScript判断是否移动设备

 functionisMobile(){     if(typeof this._isMobile === 'boolean'){        return this._isMobile;     }     varscreenWidth = this.getScreenWidth();     varfixViewPortsExperiment = rendererModel.runningExperiments.FixViewport ||rendererModel.runningExperiments.fixviewport;     varfixViewPortsExperimentRunning = fixViewPortsExperiment &&(fixViewPortsExperiment.toLowerCase() === "new");    if(!fixViewPortsExperiment){        if(!this.isAppleMobileDevice()){            screenWidth = screenWidth/window.devicePixelRatio;         }     }     varisMobileScreenSize = screenWidth < 600;     varisMobileUserAgent = false;    this._isMobile = isMobileScreenSize && this.isTouchScreen();     returnthis._isMobile; }

32、原生JavaScript判断是否移动设备访问

function isMobileUserAgent(){    return(/iphone|ipod|android.*mobile|windows.*phone|blackberry.*mobile/i.test(window.navigator.userAgent.toLowerCase()));}

33、原生JavaScript判断是否苹果移动设备访问

function isAppleMobileDevice(){    return(/iphone|ipod|ipad|Macintosh/i.test(navigator.userAgent.toLowerCase()));}

34、原生JavaScript判断是否安卓移动设备访问

function isAndroidMobileDevice(){    return(/android/i.test(navigator.userAgent.toLowerCase()));}

35、原生JavaScript判断是否Touch屏幕

function isTouchScreen(){    return(('ontouchstart' in window) || window.DocumentTouch && documentinstanceof DocumentTouch);}

36、原生JavaScript判断是否在安卓上的谷歌浏览器

 functionisNewChromeOnAndroid(){    if(this.isAndroidMobileDevice()){         varuserAgent = navigator.userAgent.toLowerCase();        if((/chrome/i.test(userAgent))){            var parts = userAgent.split('chrome/');              var fullVersionString = parts[1].split(" ")[0];            var versionString = fullVersionString.split('.')[0];            var version = parseInt(versionString);              if(version >= 27){                return true;             }         }     }     returnfalse; }

37、原生JavaScript判断是否打开视窗

function isViewportOpen() {    return!!document.getElementById('wixMobileViewport');}

38、原生JavaScript获取移动设备初始化大小

 functiongetInitZoom(){    if(!this._initZoom){         varscreenWidth = Math.min(screen.height, screen.width);        if(this.isAndroidMobileDevice() &&!this.isNewChromeOnAndroid()){            screenWidth = screenWidth/window.devicePixelRatio;         }        this._initZoom = screenWidth /document.body.offsetWidth;     }     returnthis._initZoom; }

39、原生JavaScript获取移动设备最大化大小

 functiongetZoom(){     varscreenWidth = (Math.abs(window.orientation) === 90) ? Math.max(screen.height,screen.width) : Math.min(screen.height, screen.width);    if(this.isAndroidMobileDevice() &&!this.isNewChromeOnAndroid()){        screenWidth = screenWidth/window.devicePixelRatio;     }     varFixViewPortsExperiment = rendererModel.runningExperiments.FixViewport ||rendererModel.runningExperiments.fixviewport;     varFixViewPortsExperimentRunning = FixViewPortsExperiment &&(FixViewPortsExperiment === "New" || FixViewPortsExperiment ==="new");    if(FixViewPortsExperimentRunning){        return screenWidth / window.innerWidth;     }else{        return screenWidth / document.body.offsetWidth;     } }

40、原生JavaScript获取移动设备屏幕宽度

 functiongetScreenWidth(){     varsmallerSide = Math.min(screen.width, screen.height);     varfixViewPortsExperiment = rendererModel.runningExperiments.FixViewport ||rendererModel.runningExperiments.fixviewport;     varfixViewPortsExperimentRunning = fixViewPortsExperiment &&(fixViewPortsExperiment.toLowerCase() === "new");    if(fixViewPortsExperiment){        if(this.isAndroidMobileDevice() &&!this.isNewChromeOnAndroid()){            smallerSide = smallerSide/window.devicePixelRatio;         }     }     returnsmallerSide; }

41、原生JavaScript完美判断是否为网址

function IsURL(strUrl) {    varregular =/^\b(((https?|ftp):\/\/)?[-a-z0-9]+(\.[-a-z0-9]+)*\.(?:com|edu|gov|int|mil|net|org|biz|info|name|museum|asia|coop|aero|[a-z][a-z]|((25[0-5])|(2[0-4]\d)|(1\d\d)|([1-9]\d)|\d))\b(\/[-a-z0-9_:\@&?=+,.!\/~%\$]*)?)$/i    if(regular.test(strUrl)) {        returntrue;    }    else {        returnfalse;    }}

42、原生JavaScript根据样式名称检索元素对象

 functiongetElementsByClassName(name) {     var tags= document.getElementsByTagName('*') || document.all;     var els =[];     for (vari = 0; i < tags.length; i++) {         if(tags[i].className) {            var cs = tags[i].className.split(' ');            for (var j = 0; j < cs.length; j++) {                if (name == cs[j]) {                    els.push(tags[i]);                    break                }             }         }     }     returnels }

43、原生JavaScript判断是否以某个字符串开头

String.prototype.startWith = function (s) {    returnthis.indexOf(s) == 0}

44、原生JavaScript判断是否以某个字符串结束

String.prototype.endWith = function (s) {    var d =this.length - s.length;    return (d>= 0 && this.lastIndexOf(s) == d)}

45、原生JavaScript返回IE浏览器的版本号

function getIE(){    if(window.ActiveXObject){        var v= navigator.userAgent.match(/MSIE ([^;]+)/)[1];        returnparseFloat(v.substring(0, v.indexOf(".")))    }    returnfalse}

46、原生JavaScript获取页面高度

function getPageHeight(){    var g =document, a = g.body, f = g.documentElement, d = g.compatMode =="BackCompat"            ?a            :g.documentElement;    returnMath.max(f.scrollHeight, a.scrollHeight, d.clientHeight);}

47、原生JavaScript获取页面scrollLeft

function getPageScrollLeft(){    var a =document;    returna.documentElement.scrollLeft || a.body.scrollLeft;}

48、原生JavaScript获取页面可视宽度

function getPageViewWidth(){    var d =document, a = d.compatMode == "BackCompat"            ?d.body            :d.documentElement;    returna.clientWidth;}

49、原生JavaScript获取页面宽度

function getPageWidth(){    var g =document, a = g.body, f = g.documentElement, d = g.compatMode =="BackCompat"            ?a            :g.documentElement;    returnMath.max(f.scrollWidth, a.scrollWidth, d.clientWidth);}

50、原生JavaScript获取页面scrollTop

function getPageScrollTop(){    var a =document;    returna.documentElement.scrollTop || a.body.scrollTop;}

51、原生JavaScript获取页面可视高度

function getPageViewHeight() {    var d =document, a = d.compatMode == "BackCompat"            ?d.body            :d.documentElement;    returna.clientHeight;}

52、原生JavaScript跨浏览器添加事件

 functionaddEvt(oTarget,sEvtType,fnHandle){    if(!oTarget){return;}    if(oTarget.addEventListener){        oTarget.addEventListener(sEvtType,fnHandle,false);     }elseif(oTarget.attachEvent){        oTarget.attachEvent("on" + sEvtType,fnHandle);     }else{        oTarget["on" + sEvtType] = fnHandle;     } }

53、原生JavaScript跨浏览器删除事件

 functiondelEvt(oTarget,sEvtType,fnHandle){    if(!oTarget){return;}    if(oTarget.addEventListener){        oTarget.addEventListener(sEvtType,fnHandle,false);     }elseif(oTarget.attachEvent){        oTarget.attachEvent("on" + sEvtType,fnHandle);     }else{        oTarget["on" + sEvtType] = fnHandle;     } }

54、原生JavaScript去掉url前缀

function removeUrlPrefix(a){ a=a.replace(/：/g,":").replace(/．/g,".").replace(/／/g,"/"); while(trim(a).toLowerCase().indexOf("http://")==0){   a=trim(a.replace(/http:\/\//i,""));  }  return a;}

55、原生JavaScript随机数时间戳

function uniqueId(){    vara=Math.random,b=parseInt;    returnNumber(new Date()).toString()+b(10*a())+b(10*a())+b(10*a());}

56、原生JavaScript全角半角转换,iCase:0全到半，1半到全，其他不转化

 functionchgCase(sStr,iCase){     if(typeofsStr != "string" || sStr.length <= 0 || !(iCase === 0 || iCase ==1)){        return sStr;     }     vari,oRs=[],iCode;    if(iCase){/*半->全*/        for(i=0; i<sStr.length;i+=1){             iCode = sStr.charCodeAt(i);            if(iCode == 32){                iCode = 12288;                          }else if(iCode < 127){                iCode += 65248;             }            oRs.push(String.fromCharCode(iCode));         }           }else{/*全->半*/        for(i=0; i<sStr.length;i+=1){             iCode = sStr.charCodeAt(i);            if(iCode == 12288){                iCode = 32;            }else if(iCode > 65280 && iCode < 65375){                iCode -= 65248;                          }            oRs.push(String.fromCharCode(iCode));         }            }            returnoRs.join("");         }

57、原生JavaScript确认是否键盘有效输入值

 functioncheckKey(iKey){     if(iKey== 32 || iKey == 229){return true;}/*空格和异常*/    if(iKey>47 && iKey < 58){return true;}/*数字*/    if(iKey>64 && iKey < 91){return true;}/*字母*/    if(iKey>95 && iKey < 108){return true;}/*数字键盘1*/    if(iKey>108 && iKey < 112){return true;}/*数字键盘2*/    if(iKey>185 && iKey < 193){return true;}/*符号1*/    if(iKey>218 && iKey < 223){return true;}/*符号2*/     returnfalse; }

58、原生JavaScript获取网页被卷去的位置

function getScrollXY() {    returndocument.body.scrollTop ? {        x:document.body.scrollLeft,        y:document.body.scrollTop    }: {        x:document.documentElement.scrollLeft,        y:document.documentElement.scrollTop    }}

59、原生JavaScript另一种正则日期格式化函数+调用方法

 Date.prototype.format = function(format){//author: meizz   var o = {    "M+" : this.getMonth()+1, //month    "d+" : this.getDate(),   //day    "h+" : this.getHours(),  //hour    "m+" : this.getMinutes(), //minute    "s+" : this.getSeconds(), //second    "q+" : Math.floor((this.getMonth()+3)/3),  //quarter    "S" : this.getMilliseconds() //millisecond   }  if(/(y+)/.test(format)) format=format.replace(RegExp.$1,    (this.getFullYear()+"").substr(4 - RegExp.$1.length));   for(var kin o)if(new RegExp("("+ k +")").test(format))     format =format.replace(RegExp.$1,      RegExp.$1.length==1 ? o[k] :        ("00"+ o[k]).substr((""+ o[k]).length));   returnformat; } alert(newDate().format("yyyy-MM-dd hh:mm:ss"));

60、原生JavaScript时间个性化输出功能

 /* 1、< 60s,显示为“刚刚” 2、>= 1min&& < 60 min, 显示与当前时间差“XX分钟前” 3、>= 60min&& < 1day, 显示与当前时间差“今天 XX:XX” 4、>= 1day&& < 1year, 显示日期“XX月XX日 XX:XX” 5、>=1year, 显示具体日期“XXXX年XX月XX日 XX:XX”  */ functiontimeFormat(time){   var date =new Date(time)     , curDate= new Date()     , year =date.getFullYear()     , month =date.getMonth() + 1     , day =date.getDate()     , hour =date.getHours()     , minute= date.getMinutes()     , curYear= curDate.getFullYear()     , curHour= curDate.getHours()     ,timeStr;     if(year< curYear){     timeStr =year +'年'+ month +'月'+ day +'日 '+ hour +':'+ minute;   }else{     varpastTime = curDate - date       , pastH= pastTime/3600000;       if(pastH> curHour){       timeStr= month +'月'+ day +'日 '+ hour +':'+ minute;     }elseif(pastH >= 1){       timeStr= '今天 ' + hour +':'+ minute +'分';     }else{       varpastM = curDate.getMinutes() - minute;      if(pastM > 1){        timeStr = pastM +'分钟前';       }else{        timeStr = '刚刚';       }     }   }   returntimeStr; } 

原文来自：

http://www.jq-school.com/Show.aspx?id=316