JSFiddle - React, Tailwind, and code Playground

HTML

<div id="foo">
  ...
  <span id="moo">
    ...
  </span>
  ...
</div>

JavaScript

$(function(){
var selectors = ["#foo > #moo","#moo","#moo #foo","#foo span","div#foo span#foo"];
    $.each(selectors, function(i,val){
        var t1= new Date();
    for(var i = 0;i<1000;i++)
    {
        $(val);
    }
        var t2 = new Date();
        $('body').append(val+"----"+(t2-t1)+"<br/>");
    });
});