Uppercase a javascript function

Im getting some variable for the URL, but I’m getting as a lowercase and I would like to get it uppercase. This is the javascript that I’m running. How can I get it in Uppercase as return???

thanks

    function() {
  var pageUrl = window.location.href;
  return pageUrl.split("/")[3];
}

Answer

Use toUpperCase

function foo() {
  var pageUrl = window.location.href;
  return pageUrl.split("/")[3].toUpperCase();
}

console.log(foo());