var APP = {};
   //判断指定版本是否在版本范围之间,需确保版本规范一致;比如 (..,..,..)
   APP.betweenVersion = function(curr,start,end,separator){
     if(curr == start || curr == end){
       return true;
     }
     var separator = separator || '.';
     var curr = curr.split(separator);
     var start = start.split(separator);
     var end = end.split(separator);    
     var gtStart = false;
     var ltEnd = false;
 
     gtStart = APP.gtTargetVersion( APP.compareVersionEle(curr,start) );
 
     if(!gtStart){
       return false;
     }
     return !APP.gtTargetVersion( APP.compareVersionEle(curr,end) );
 
   };
   APP.compareVersionEle = function(curr,target){
     var len = curr.length;
     var temp = [];
     var left,right;
     for(var i=;i<len;i++){
 
       left = +curr[i];
       right = +target[i];
 
       if(left == right){
         temp.push();
       }else if(left > right){
         temp.push();
       }else{
         temp.push(-);
       }
     }
     return temp;
   };
   APP.gtTargetVersion = function(arr){
     var res = true;
     var curr,next;
     for(var i=,len=arr.length;i<len;i++){
       curr = arr[i];
       next = arr[i+];
       if( curr>next ){
         if(curr == ){
           res = false;
           break;
         }
         if(curr == ){
           res = true;
           break;
         }        
       }else if(curr == next){
         if(curr == -){
           res = false;
           break;
         }
         if(curr == ){
           res = true;
           break;
         }
       }else{
         if(curr == -){
           res = false;
           break;
         }
         if(curr == ){
           res = true;
           break;
         }
       }
     }
     // console.log(res);
     return res;
   }
   var res = APP.betweenVersion('...','...','...','.');
 console.log(res);

//获取IE浏览器的版本号
//返回数值，显示IE的主版本号
function getIEVer() {
 var ua = navigator.userAgent; //获取用户端信息
 var b = ua.indexOf("MSIE "); //检测特殊字符串"MSIE "的位置
 if (b < 0) {
  return 0;
 }
 return parseFloat(ua.substring(b + 5, ua.indexOf(";", b))); //截取版本号字符串，并转换为数值
}
alert(getIEVer()); //返回数值8(我的IE8)

var ua = navigator.userAgent.toLowerCase(); //获取用户端信息
var info = {
 ie: /msie/.test(ua) && !/opera/.test(ua),  //匹配IE浏览器
 op: /opera/.test(ua),  //匹配Opera浏览器
 sa: /version.*safari/.test(ua),  //匹配Safari浏览器
 ch: /chrome/.test(ua),  //匹配Chrome浏览器
 ff: /gecko/.test(ua) && !/webkit/.test(ua)  //匹配Firefox浏览器
};
(info.ie) && alert("IE浏览器");
(info.op) && alert("Opera浏览器");
(info.sa) && alert("Safari浏览器");
(info.ff) && alert("Firefox浏览器");
(info.ch) && alert("Chrome浏览器");

var isIE = (navigator.appName == "Microsoft Internet Explorer");

//获取IE浏览器的版本号
//返回数值，显示IE的主版本号
function getIEVer() {
 var ua = navigator.userAgent; //获取用户端信息
 var b = ua.indexOf("MSIE "); //检测特殊字符串"MSIE "的位置
 if (b < 0) {
  return 0;
 }
 return parseFloat(ua.substring(b + 5, ua.indexOf(";", b))); //截取版本号字符串，并转换为数值
}
alert(getIEVer()); //返回数值7

var isWin = (navigator.userAgent.indexOf("Win") != -1); //如果是Windows系统，则返回true
var isMac = (navigator.userAgent.indexOf("Mac") != -1);  //如果是Macintosh系统，则返回true
var isUnix = (navigator.userAgent.indexOf("X11") != -1);  //如果是Unix系统，则返回true
var isLinux = (navigator.userAgent.indexOf("Linux") != -1);  //如果是Linux系统，则返回true