js判断是pc或移动端核心代码

<script type="text/javascript">
   var os = function () {
       var ua = navigator.userAgent,
       isWindowsPhone = /(?:Windows Phone)/.test(ua),
       isSymbian = /(?:SymbianOS)/.test(ua) || isWindowsPhone,
       isAndroid = /(?:Android)/.test(ua),
       isFireFox = /(?:Firefox)/.test(ua),
       isChrome = /(?:Chrome|CriOS)/.test(ua),
       isTablet = /(?:iPad|PlayBook)/.test(ua) || (isAndroid &&       !/(?:Mobile)/.test(ua)) || (isFireFox && /(?:Tablet)/.test(ua)),
       isPhone = /(?:iPhone)/.test(ua) && !isTablet,
       isPc = !isPhone && !isAndroid && !isSymbian;
       
       return {
              isTablet: isTablet,
              isPhone: isPhone,
              isAndroid: isAndroid,
              isPc: isPc
       };
   }();
   if(os.isPc){
      location.replace("http://www.onlymid.com.cn/");
   }

       
   if (os.isAndroid || os.isPhone) {
      location.replace('http://www.onlymid.com.cn/html/2016shujia/wap/');
   } else if (os.isTablet) {
      location.replace('http://www.onlymid.com.cn/html/2016shujia/wap/');
   }
</script>