1.手机类型判断

var BrowserInfo = {
userAgent: navigator.userAgent.toLowerCase()
isAndroid: Boolean(navigator.userAgent.match(/android/ig)),
isIphone: Boolean(navigator.userAgent.match(/iphone|ipod/ig)),
isIpad: Boolean(navigator.userAgent.match(/ipad/ig)),
isWeixin: Boolean(navigator.userAgent.match(/MicroMessenger/ig)),
}

2.返回字符串长度，汉子计数为2

function strLength(str) {
var a = 0;
for (var i = 0; i < str.length; i++) {
  if (str.charCodeAt(i) > 255)
      a += 2;//按照预期计数增加2
  else
      a++;
}
return a;
}

3.获取url中的参数

function GetQueryStringRegExp(name,url) {
var reg = new RegExp("(^|\?|&)" + name + "=([^&]*)(\s|&|$)", "i");
if (reg.test(url)) return decodeURIComponent(RegExp.$2.replace(/+/g, " ")); return "";
}

4.js绑定事件适用于任何浏览器的元素绑定

function eventBind(obj, eventType, callBack) {
  if (obj.addEventListener) {
      obj.addEventListener(eventType, callBack, false);
  }
  else if (window.attachEvent) {
      obj.attachEvent('on' + eventType, callBack);
  }
  else {
      obj['on' + eventType] = callBack;
  }
};
eventBind(document, 'click', bodyClick);

5.获得当前浏览器JS的版本

function getjsversion(){
var n = navigator;
var u = n.userAgent;
var apn = n.appName;
var v = n.appVersion;
var ie = v.indexOf('MSIE ');
if (ie > 0){
  apv = parseInt(i = v.substring(ie + 5));
  if (apv > 3) {
      apv = parseFloat(i);
  }
} else {
  apv = parseFloat(v);
}
var isie = (apn == 'Microsoft Internet Explorer');
var ismac = (u.indexOf('Mac') >= 0);
var javascriptVersion = "1.0";
if (String && String.prototype) {
  javascriptVersion = '1.1';
  if (javascriptVersion.match) {
      javascriptVersion = '1.2';
      var tm = new Date;
      if (tm.setUTCDate) {
          javascriptVersion = '1.3';
          if (isie && ismac && apv >= 5) javascriptVersion = '1.4';
          var pn = 0;
          if (pn.toPrecision) {
              javascriptVersion = '1.5';
              a = new Array;
              if (a.forEach) {
                  javascriptVersion = '1.6';
                  i = 0;
                  o = new Object;
                  tcf = new Function('o', 'var e,i=0;try{i=new Iterator(o)}catch(e){}return i');
                  i = tcf(o);
                  if (i && i.next) {
                      javascriptVersion = '1.7';
                  }
              }
          }
      }
  }
}
return javascriptVersion;
}

6.获取当前点击事件的Object对象

function getEvent() {
if (document.all) {
   return window.event; //如果是ie
}
func = getEvent.caller;
while (func != null) {
   var arg0 = func.arguments[0];
   if (arg0) {
       if ((arg0.constructor == Event || arg0.constructor == MouseEvent)
|| (typeof (arg0) == "object" && arg0.preventDefault && arg0.stopPropagation)) {
           return arg0;
       }
   }
   func = func.caller;
}
return null;
};

7.字符串截取方法

getCharactersLen: function (charStr, cutCount) {
   if (charStr == null || charStr == '') return '';
   var totalCount = 0;
   var newStr = '';
   for (var i = 0; i < charStr.length; i++) {
       var c = charStr.charCodeAt(i);
       if (c < 255 && c > 0) {
           totalCount++;
       } else {
           totalCount += 2;
       }
       if (totalCount >= cutCount) {
           newStr += charStr.charAt(i);
           break;
       }
       else {
           newStr += charStr.charAt(i);
       }
   }
   return newStr;
}

8.JS弹出新窗口全屏

var tmp = window.open("about:blank", "", "fullscreen=1")
                       tmp.moveTo(0, 0);
                       tmp.resizeTo(screen.width + 20, screen.height);
                       tmp.focus();
                       tmp.location.href = 'http://www.che168.com/pinggu/eva_' + msgResult.message[0] + '.html';

var config_ = "left=0,top=0,width=" + (window.screen.Width) + ",height=" + (window.screen.Height);
                       window.open('http://www.che168.com/pinggu/eva_' + msgResult.message[0] + '.html', "winHanle", config_);
//模拟form提交打开新页面
var f = document.createElement("form");
                       f.setAttribute('action', 'http://www.che168.com/pinggu/eva_' + msgResult.message[0] + '.html');
                       f.target = '_blank';
                       document.body.appendChild(f);
                       f.submit();

9. 全选/全不选

function selectAll(objSelect) {
       if (objSelect.checked == true) {
           $("input[name='chkId']").attr("checked", true);
           $("input[name='chkAll']").attr("checked", true);
       }
       else if (objSelect.checked == false) {
           $("input[name='chkId']").attr("checked", false);
           $("input[name='chkAll']").attr("checked", false);
       }
   }

10. js判断浏览器

判断是否是 IE 浏览器
if (document.all){
   alert(”IE浏览器”);
}else{
   alert(”非IE浏览器”);
}
if (!!window.ActiveXObject){
   alert(”IE浏览器”);
}else{
   alert(”非IE浏览器”);
}
判断是IE几
var isIE=!!window.ActiveXObject;
var isIE6=isIE&&!window.XMLHttpRequest;
var isIE8=isIE&&!!document.documentMode;
var isIE7=isIE&&!isIE6&&!isIE8;
if (isIE){
if (isIE6){
   alert(”ie6″);
}else if (isIE8){
   alert(”ie8″);
}else if (isIE7){
   alert(”ie7″);
}
}

11.判断浏览器

function getOs() {
if (navigator.userAgent.indexOf("MSIE 8.0") > 0) {
   return "MSIE8";
}
else if (navigator.userAgent.indexOf("MSIE 6.0") > 0) {
   return "MSIE6";
}
else if (navigator.userAgent.indexOf("MSIE 7.0") > 0) {
   return "MSIE7";
}
else if (isFirefox = navigator.userAgent.indexOf("Firefox") > 0) {
   return "Firefox";
}
if (navigator.userAgent.indexOf("Chrome") > 0) {
   return "Chrome";
}
else {
   return "Other";
}
}

12.JS判断两个日期大小适合 2012-09-09 与2012-9-9 两种格式的对比

//得到日期值并转化成日期格式，replace(/-/g, "/")是根据验证表达式把日期转化成长日期格式，这样再进行判断就好判断了
   function ValidateDate() {
       var beginDate = $("#t_datestart").val();
       var endDate = $("#t_dateend").val();
       if (beginDate.length > 0 && endDate.length>0) {
           var sDate = new Date(beginDate.replace(/-/g, "/"));
           var eDate= new Date(endDate.replace(/-/g, "/"));
           if (sDate > eDate) {
               alert('开始日期要小于结束日期');
               return false;
           }
       }
   }

13.移除事件

this.moveBind = function (objId, eventType, callBack) {
var obj = document.getElementById(objId);
if (obj.removeEventListener) {
   obj.removeEventListener(eventType, callBack, false);
}
else if (window.detachEvent) {
   obj.detachEvent('on' + eventType, callBack);
}
else {
   obj['on' + eventType] = null;
}
}

14.回车提交

$("id").onkeypress = function (event) {
event = (event) ? event : ((window.event) ? window.event : "")
keyCode = event.keyCode ? event.keyCode : (event.which ? event.which : event.charCode);
if (keyCode == 13) {
   $("SubmitLogin").onclick();
}
}

15.JS 执行计时器

timeStart = new Date().getTime();
timesEnd = new Date().getTime();
document.getElementById("time").innerHTML = timesEnd - timeStart;

16.JS 写Cookie

function setCookie(name, value, expires, path, domain) {
if (!expires) expires = -1;
if (!path) path = "/";
var d = "" + name + "=" + value;
var e;
if (expires < 0) {
   e = "";
}
else if (expires == 0) {
   var f = new Date(1970, 1, 1);
   e = ";expires=" + f.toUTCString();
}
else {
   var now = new Date();
   var f = new Date(now.getTime() + expires * 1000);
   e = ";expires=" + f.toUTCString();
}
var dm;
if (!domain) {
   dm = "";
}
else {
   dm = ";domain=" + domain;
}
document.cookie = name + "=" + value + ";path=" + path + e + dm;
};

17. JS读Cookie

function readCookie(name) {
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for (var i = 0; i < ca.length; i++) {
   var c = ca[i];
   while (c.charAt(0) == ' ') c = c.substring(1, c.length);
   if (c.indexOf(nameEQ) == 0) {
       return decodeURIComponent(c.substring(nameEQ.length, c.length))
   }
} return null
}

18. Ajax请求

C.ajax = function (args) {
var self = this;
this.options = {
   type: 'GET',
   async: true,
   contentType: 'application/x-www-form-urlencoded',
   url: 'about:blank',
   data: null,
   success: {},
   error: {}
};
this.getXmlHttp = function () {
   var xmlHttp;
   try {
       xmlhttp = new XMLHttpRequest();
   }
   catch (e) {
       try {
           xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
       }
       catch (e) {
           xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
       }
   }
   if (!xmlhttp) {
       alert('您的浏览器不支持AJAX');
       return false;
   }
   return xmlhttp;
};
this.send = function () {
   C.each(self.options, function (key, val) {
       self.options[key] = (args[key] == null) ? val : args[key];
   });

   var xmlHttp = new self.getXmlHttp();
   if (self.options.type.toUpperCase() == 'GET') {
       xmlHttp.open(self.options.type, self.options.url + (self.options.data == null ? "" : ((/[?]$/.test(self.options.url) ? '&' : '?') + self.options.data)), self.options.async);
   }
   else {
       xmlHttp.open(self.options.type, self.options.url, self.options.async);
       xmlHttp.setRequestHeader('Content-Length', self.options.data.length);
   }
   xmlHttp.setRequestHeader('Content-Type', self.options.contentType);
   xmlHttp.onreadystatechange = function () {
       if (xmlHttp.readyState == 4) {
           if (xmlHttp.status == 200 || xmlHttp.status == 0) {
               if (typeof self.options.success == 'function') self.options.success(xmlHttp.responseText);
               xmlHttp = null;
           }
           else {
               if (typeof self.options.error == 'function') self.options.error('Server Status: ' + xmlHttp.status);
           }
       }
   };

   xmlHttp.send(self.options.type.toUpperCase() == 'POST' ? self.options.data.toString() : null);
};
this.send();
};

19. JS StringBuilder 用法

function StringBuilder() {
this.strings = new Array;
};
StringBuilder.prototype.append = function (str) {
this.strings.push(str);
};
StringBuilder.prototype.toString = function () {
return this.strings.join('');
};

20. JS加载到顶部LoadJS

function loadJS (url, fn) {
   var ss = document.getElementsByName('script'),
       loaded = false;
   for (var i = 0, len = ss.length; i < len; i++) {
       if (ss[i].src && ss[i].getAttribute('src') == url) {
           loaded = true;
           break;
       }
   }
   if (loaded) {
       if (fn && typeof fn != 'undefined' && fn instanceof Function) fn();
       return false;
   }
   var s = document.createElement('script'),
       b = false;
   s.setAttribute('type', 'text/javascript');
   s.setAttribute('src', url);
   s.onload = s.onreadystatechange = function () {
       if (!b && (!this.readyState || this.readyState == 'loaded' || this.readyState == 'complete')) {
           b = true;
           if (fn && typeof fn != 'undefined' && fn instanceof Function) fn();
       }
   };
   document.getElementsByTagName('head')[0].appendChild(s);
},
bind: function (objId, eventType, callBack) {  //适用于任何浏览器的绑定
   var obj = document.getElementById(objId);
   if (obj.addEventListener) {
       obj.addEventListener(eventType, callBack, false);
   }
   else if (window.attachEvent) {
       obj.attachEvent('on' + eventType, callBack);
   }
   else {
       obj['on' + eventType] = callBack;
   }
}

function JSLoad (args) {
   s = document.createElement("script");
   s.setAttribute("type", "text/javascript");
   s.setAttribute("src", args.url);
   s.onload = s.onreadystatechange = function () {
       if (!s.readyState || s.readyState == "loaded" || s.readyState == "complete") {
           if (typeof args.callback == "function") args.callback(this, args);
           s.onload = s.onreadystatechange = null;
           try {
               s.parentNode && s.parentNode.removeChild(s);
           } catch (e) { }
       }
   };
   document.getElementsByTagName("head")[0].appendChild(s);
}

21.清空LoadJS加载到顶部的js引用

function ClearHeadJs  (src) {
   var js = document.getElementsByTagName('head')[0].children;
   var obj = null;
   for (var i = 0; i < js.length; i++) {
       if (js[i].tagName.toLowerCase() == "script" && js[i].attributes['src'].value.indexOf(src) > 0) {
           obj = js[i];
       }
   }
   document.getElementsByTagName('head')[0].removeChild(obj);
};

22. JS替换非法字符主要用在密码验证上出现的特殊字符

function URLencode(sStr) {
return escape(sStr).replace(/+/g, '%2B').replace(/"/g, '%22').replace(/'/g, '%27').replace(///g, '%2F');
};

23. 按Ctrl + Entert 直接提交表单

document.body.onkeydown = function (evt) {
evt = evt ? evt : (window.event ? window.event : null);
if (13 == evt.keyCode && evt.ctrlKey) {

   evt.returnValue = false;
   evt.cancel = true;
   PostData();
}
};

24.获取当前时间

function GetCurrentDate() {
   var d = new Date();
   var y = d.getYear()+1900;
   month = add_zero(d.getMonth() + 1),
   days = add_zero(d.getDate()),
   hours = add_zero(d.getHours());
   minutes = add_zero(d.getMinutes()),
   seconds = add_zero(d.getSeconds());
   var str = y + '-' + month + '-' + days + ' ' + hours + ':' + minutes + ':' + seconds;
   return str;
};
function add_zero(temp) {
   if (temp < 10) return "0" + temp;
   else return temp;
}

25. Js去掉空格方法

String.prototype.Trim = function()
{ return this.replace(/(^s*)|(s*$)/g, ""); }
String.prototype.LTrim = function()
{return this.replace(/(^s*)/g, "");}
String.prototype.RTrim = function()
{return this.replace(/(s*$)/g, "");}

26. Js动态移除head里的js引用

this.ClearHeadJs = function (src) {
var js = document.getElementsByTagName('head')[0].children;
var obj = null;
for (var i = 0; i < js.length; i++) {
   if (js[i].tagName.toLowerCase() == "script" && js[i].attributes['src'].value.indexOf(src) > 0) {
       obj = js[i];
   }
}
document.getElementsByTagName('head')[0].removeChild(obj);
};

27.整个UL点击事件加在UL里的onclick里

function CreateFrom(url, params) {
var f = document.createElement("form");
f.setAttribute("action", url);
for (var i = 0; i < params.length; i++) {
    var input = document.createElement("input");
    input.setAttribute("type", "hidden");
    input.setAttribute("name", params[i].paramName);
    input.setAttribute("value", params[i].paramValue);
    f.appendChild(input);
}
f.target = "_blank";
document.body.appendChild(f);
f.submit();
};

28. 判断浏览器使用的是哪个 JS 版本

<script language="javascript">
 var jsversion = 1.0;
</script>
<script language="javascript1.1">
 jsversion = 1.1;
</script>
<script language="javascript1.2">
 jsversion = 1.2;
</script>
<script language="javascript1.3">
 jsversion = 1.3;
</script>
<script language="javascript1.4">
 jsversion = 1.4;
</script>
<script language="javascript1.5">
 jsversion = 1.5;
</script>
<script language="javascript1.6">
 jsversion = 1.6;
</script>
<script language="javascript1.7">
 jsversion = 1.7;
</script>
<script language="javascript1.8">
 jsversion = 1.8;
</script>
<script language="javascript1.9">
 jsversion = 1.9;
</script>
<script language="javascript2.0">
 jsversion = 2.0;
</script>
alert(jsversion);

原文：JavaScript 常用方法总结
作者：花落如海