I am trying add classname and remove classname based on the resolution using jquery.

Here is my Jquery code. In mobile mode I am getting totopDesk in desktop mode I am getting totop_tab only in tablet mode I am getting correct class. What I am doing wrong here

function isMobile(){
    if($(window).width() <= 575){
        return true;
   } else {
       return false;
   }
 }
function isTab(){
   if($(window).width() > 575 && $(window).width() <= 992){
      return true;
    } else {
      return false;
    }
  }
 function isDesktop(){
    if($(window).width() >= 992){
        return true;
        } else {
        return false;
      }
  }

$(window).resize(function ()
  {
     if (isMobile()) {
         goMobile()
    }
   else if (isTab()) {
       goTablet()
     } 
    else {
       goDesktop();
     } 
  })

    function goDesktop()
{
    $("#go_btn").addClass("totopDesk");
    $("#go_btn").removeClass("totop_tab");  
    $("#go_btn").removeClass("totop_mob");
}
function goMobile() {
    $("#go_btn").addClass("totop_mob");
    $("#go_btn").removeClass("totopDesk");
    $("#go_btn").removeClass("totop_tab");
}
function goTablet() {
    $("#go_btn").addClass("totop_tab");
    $("#go_btn").removeClass("totop_mob");
    $("#go_btn").removeClass("totop");
    $("#go_btn").removeClass("totopDesk");  
}

without Jquery simple using @Media query I am getting this issue

When I am in Tablet mode in the inspect element 48em class got strike out it showing only deskop css