//isPC(): 检测客户端环境是否是pc端

     function isPC(){

         let userAgent = navigator.userAgent;

         let agents = ["Android", "iPhone", "SymbianOS", "Windows Phone", "iPad", "iPod"];

         let ispc = true, v;

         for(v = 0; v < agents.length; v++){

             if (userAgent.indexOf(agents[v]) > 0){ispc = false; break;}

         }

         return ispc;

     }

     //调用

     document.write(isPC());//true