字符串长度截取

function cutstr(str, len) {    var temp,        icount = 0,        patrn = /[^\x00-\xff]/，        strre = "";    for (var i = 0; i < str.length; i++) {        if (icount < len - 1) {            temp = str.substr(i, 1);                if (patrn.exec(temp) == null) {                   icount = icount + 1            } else {                icount = icount + 2            }            strre += temp            } else {            break;        }    }    return strre + "..."}

替换全部

String.prototype.replaceAll = function(s1, s2) {    return this.replace(new RegExp(s1, "gm"), s2)}

清除空格

String.prototype.trim = function() {    var reExtraSpace = /^\s*(.*?)\s+$/;    return this.replace(reExtraSpace, "$1")}

清除左空格/右空格

function ltrim(s){ return s.replace( /^(\s*|　*)/, ""); }function rtrim(s){ return s.replace( /(\s*|　*)$/, ""); }

判断是否以某个字符串开头

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

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)}

转义html标签

function HtmlEncode(text) {    return text.replace(/&/g, '&').replace(/\"/g, '"').replace(//g, '>')}

时间日期格式转换

Date.prototype.Format = function(formatStr) {    var str = formatStr;    var Week = ['日', '一', '二', '三', '四', '五', '六'];    str = str.replace(/yyyy|YYYY/, this.getFullYear());    str = str.replace(/yy|YY/, (this.getYear() % 100) > 9 ? (this.getYear() % 100).toString() : '0' + (this.getYear() % 100));    str = str.replace(/MM/, (this.getMonth() + 1) > 9 ? (this.getMonth() + 1).toString() : '0' + (this.getMonth() + 1));    str = str.replace(/M/g, (this.getMonth() + 1));    str = str.replace(/w|W/g, Week[this.getDay()]);    str = str.replace(/dd|DD/, this.getDate() > 9 ? this.getDate().toString() : '0' + this.getDate());    str = str.replace(/d|D/g, this.getDate());    str = str.replace(/hh|HH/, this.getHours() > 9 ? this.getHours().toString() : '0' + this.getHours());    str = str.replace(/h|H/g, this.getHours());    str = str.replace(/mm/, this.getMinutes() > 9 ? this.getMinutes().toString() : '0' + this.getMinutes());    str = str.replace(/m/g, this.getMinutes());    str = str.replace(/ss|SS/, this.getSeconds() > 9 ? this.getSeconds().toString() : '0' + this.getSeconds());    str = str.replace(/s|S/g, this.getSeconds());    return str}

判断是否为数字类型

function isDigit(value) {    var patrn = /^[0-9]*$/;    if (patrn.exec(value) == null || value == "") {        return false    } else {        return true    }}

设置cookie值

function setCookie(name, value, Hours) {    var d = new Date();    var offset = 8;    var utc = d.getTime() + (d.getTimezoneOffset() * 60000);    var nd = utc + (3600000 * offset);    var exp = new Date(nd);    exp.setTime(exp.getTime() + Hours * 60 * 60 * 1000);    document.cookie = name + "=" + escape(value) + ";path=/;expires=" + exp.toGMTString() + ";domain=360doc.com;"}

获取cookie值

function getCookie(name) {    var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));    if (arr != null) return unescape(arr[2]);    return null}

加入收藏夹

function AddFavorite(sURL, sTitle) {    try {        window.external.addFavorite(sURL, sTitle)    } catch(e) {        try {            window.sidebar.addPanel(sTitle, sURL, "")        } catch(e) {            alert("加入收藏失败，请使用Ctrl+D进行添加")        }    }}

设为首页

function setHomepage() {    if (document.all) {        document.body.style.behavior = 'url(#default#homepage)';        document.body.setHomePage('http://w3cboy.com')    } else if (window.sidebar) {        if (window.netscape) {            try {                netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect")            } catch(e) {                alert("该操作被浏览器拒绝，如果想启用该功能，请在地址栏内输入 about:config,然后将项 signed.applets.codebase_principal_support 值该为true")                }        }        var prefs = Components.classes['@mozilla.org/preferences-service;1'].getService(Components.interfaces.nsIPrefBranch);        prefs.setCharPref('browser.startup.homepage', 'http://w3cboy.com')    }}

加载样式文件

function LoadStyle(url) {    try {        document.createStyleSheet(url)    } catch(e) {        var cssLink = document.createElement('link');        cssLink.rel = 'stylesheet';        cssLink.type = 'text/css';        cssLink.href = url;        var head = document.getElementsByTagName('head')[0];        head.appendChild(cssLink)    }}

返回脚本内容

function evalscript(s) {    if(s.indexOf('
    
     ]*?>([^\x00]*?)<\/script>/ig;    var arr = [];    while(arr = p.exec(s)) {        var p1 = /
     
      ]*?src=\"([^\>]*?)\"[^\>]*?(reload=\"1\")?(?:charset=\"([\w\-]+?)\")?><\/script>/i;        var arr1 = [];        arr1 = p1.exec(arr[0]);        if(arr1) {            appendscript(arr1[1], '', arr1[2], arr1[3]);        } else {            p1 = /
      
       ([^\x00]+?)<\/script>/i;            arr1 = p1.exec(arr[0]);            appendscript('', arr1[2], arr1[1].indexOf('reload=') != -1);        }    }    return s;}
      
     
    

清除脚本内容

function stripscript(s) {    return s.replace(/
    
     .*?<\/script>/ig, '');}
    

动态加载脚本文件

function appendscript(src, text, reload, charset) {    var id = hash(src + text);    if(!reload && in_array(id, evalscripts)) return;    if(reload && $(id)) {        $(id).parentNode.removeChild($(id));    }    evalscripts.push(id);    var scriptNode = document.createElement("script");    scriptNode.type = "text/javascript";    scriptNode.id = id;    scriptNode.charset = charset ? charset : (BROWSER.firefox ? document.characterSet : document.charset);    try {        if(src) {            scriptNode.src = src;            scriptNode.onloadDone = false;            scriptNode.onload = function () {                scriptNode.onloadDone = true;                JSLOADED[src] = 1;             };             scriptNode.onreadystatechange = function () {                 if((scriptNode.readyState == 'loaded' || scriptNode.readyState == 'complete') && !scriptNode.onloadDone) {                    scriptNode.onloadDone = true;                    JSLOADED[src] = 1;                }             };        } else if(text){            scriptNode.text = text;        }        document.getElementsByTagName('head')[0].appendChild(scriptNode);    } catch(e) {}}

返回按ID检索的元素对象

function $(id) {    return !id ? null : document.getElementById(id);}

跨浏览器绑定事件

function addEventSamp(obj,evt,fn){    if(!oTarget){return;}    if (obj.addEventListener) {        obj.addEventListener(evt, fn, false);    }else if(obj.attachEvent){        obj.attachEvent('on'+evt,fn);    }else{        oTarget["on" + sEvtType] = fn;    }}

跨浏览器删除事件

function delEvt(obj,evt,fn){    if(!obj){return;}    if(obj.addEventListener){        obj.addEventListener(evt,fn,false);    }else if(oTarget.attachEvent){        obj.attachEvent("on" + evt,fn);    }else{        obj["on" + evt] = fn;    }}