js判断是否为手机或是pc

$(function(){
  var mobile_flag = isMobile(); // true为PC端，false为手机端

  if(mobile_flag){
      $("#fh5co-main").css({"width": "100%", "float": "right"});
      $("#trademark").css({"margin-left": "48px","margin-top": "16px"});
  }
  console.log(mobile_flag);
});

function isMobile() {
  var userAgentInfo = navigator.userAgent;

  var mobileAgents = [ "Android", "iPhone", "SymbianOS", "Windows Phone", "iPad","iPod"];

  var mobile_flag = false;

  //根据userAgent判断是否是手机
  for (var v = 0; v < mobileAgents.length; v++) {
      if (userAgentInfo.indexOf(mobileAgents[v]) > 0) {
          mobile_flag = true;
          break;
      }
  }

   var screen_width = window.screen.width;
   var screen_height = window.screen.height;    

   //根据屏幕分辨率判断是否是手机
   if(screen_width < 500 && screen_height < 800){
       mobile_flag = true;
   }

   return mobile_flag;
}

　　

来源：https://www.cnblogs.com/JamyWong/p/12522109.html