js 是否可以识别PAD和PC

 js 获取浏览器操作系统信息 var BrowserDetect = {
   init: function () {
    this.browser = this.searchString(this.dataBrowser) || "An unknown browser";
    this.version = this.searchVersion(navigator.userAgent)
     || this.searchVersion(navigator.appVersion)
     || "an unknown version";
    this.OS = this.searchString(this.dataOS) || "an unknown OS";
   },
   searchString: function (data) {
    for (var i=0;i<data.length;i++) {
     var dataString = data[i].string;
     var dataProp = data[i].prop;
     this.versionSearchString = data[i].versionSearch || data[i].identity;
     if (dataString) {
      if (dataString.indexOf(data[i].subString) != -1)
       return data[i].identity;
     }
     else if (dataProp)
      return data[i].identity;
    }
   },
   searchVersion: function (dataString) {
    var index = dataString.indexOf(this.versionSearchString);
    if (index == -1) return;
    return parseFloat(dataString.substring(index+this.versionSearchString.length+1));
   },
   dataBrowser: [
    {
     string: navigator.userAgent,
     subString: "Chrome",
     identity: "Chrome"
    },
    { string: navigator.userAgent,
     subString: "OmniWeb",
     versionSearch: "OmniWeb/",
     identity: "OmniWeb"
    },
    {
     string: navigator.vendor,
     subString: "Apple",
     identity: "Safari",
     versionSearch: "Version"
    },
    {
     prop: window.opera,
     identity: "Opera"
    },
    {
     string: navigator.vendor,
     subString: "iCab",
     identity: "iCab"
    },
    {
     string: navigator.vendor,
     subString: "KDE",
     identity: "Konqueror"
    },
    {
     string: navigator.userAgent,
     subString: "Firefox",
     identity: "Firefox"
    },
    {
     string: navigator.vendor,
     subString: "Camino",
     identity: "Camino"
    },
    {   // for newer Netscapes (6+)
     string: navigator.userAgent,
     subString: "Netscape",
     identity: "Netscape"
    },
    {
     string: navigator.userAgent,
     subString: "MSIE",
     identity: "Explorer",
     versionSearch: "MSIE"
    },
    {
     string: navigator.userAgent,
     subString: "Gecko",
     identity: "Mozilla",
     versionSearch: "rv"
    },
    {    // for older Netscapes (4-)
     string: navigator.userAgent,
     subString: "Mozilla",
     identity: "Netscape",
     versionSearch: "Mozilla"
    }
   ],
   dataOS : [
    {
     string: navigator.platform,
     subString: "Win",
     identity: "Windows"
    },
    {
     string: navigator.platform,
     subString: "Mac",
     identity: "Mac"
    },
    {
     string: navigator.userAgent,
     subString: "iPhone",
     identity: "iPhone/iPod"
      },
    {
     string: navigator.platform,
     subString: "Linux",
     identity: "Linux"
    }
   ]


};


BrowserDetect.init();
//alert( BrowserDetect.OS);
//alert( BrowserDetect.browser);




        var Sys = {}; 
        var ua = navigator.userAgent.toLowerCase(); 
        var s; 
        (s = ua.match(/msie ([\d.]+)/)) ? Sys.ie = s[1] : 
        (s = ua.match(/firefox\/([\d.]+)/)) ? Sys.firefox = s[1] : 
        (s = ua.match(/chrome\/([\d.]+)/)) ? Sys.chrome = s[1] : 
        (s = ua.match(/opera.([\d.]+)/)) ? Sys.opera = s[1] : 
        (s = ua.match(/version\/([\d.]+).*safari/)) ? Sys.safari = s[1] : 0;


        var userAgentstr="";
        if (Sys.ie) userAgentstr=('IE: ' + Sys.ie); 
        if (Sys.firefox) userAgentstr=('Firefox: ' + Sys.firefox); 
        if (Sys.chrome) userAgentstr=('Chrome: ' + Sys.chrome); 
        if (Sys.opera) userAgentstr=('Opera: ' + Sys.opera); 
        if (Sys.safari) userAgentstr=('Safari: ' + Sys.safari);