js判断是否是移动端自动跳转到wap页面代码

<script type="text/javascript">
        function is_mobile(){
          var regex_match=/(nokia|iphone|android|motorola|^mot-|softbank|foma|docomo|kddi|up.browser|up.link|htc|dopod|blazer|netfront|helio|hosin|huawei|novarra|CoolPad|webos|techfaith|palmsource|blackberry|alcatel|amoi|ktouch|nexian|samsung|^sam-|s[cg]h|^lge|ericsson|philips|sagem|wellcom|bunjalloo|maui|symbian|smartphone|midp|wap|phone|windows ce|iemobile|^spice|^bird|^zte-|longcos|pantech|gionee|^sie-|portalmmm|jigs browser|hiptop|^benq|haier|^lct|operas*mobi|opera*mini|320x320|240x320|176x220)/i;
          var u=navigator.userAgent;
          if (null==u){
            return true;
          }
          var result = regex_match.exec(u);
          if(null==result){
            return false
          }
          else{
            return true
          }
        }
        if(is_mobile()){
          //document.location.href='wap/';
        }else{
          //document.location.href='pc/';
        }
    </script>