for the "signs of an advancing web" blog post https://edm00se.io/web/sings-of-the-web-advancing

betterWay.js

const parm = new URLSearchParams(window.location.search);
console.log(parm.get('foo')); // 'bar'

getQueryParametersOldWay.js

function getQueryParam(searchKey){
  var qs = window.location.split('?')[1];
  var parmAr = qs.split('&');
  var parm = {};
  for(i = 0; i<parmAr.length; i++) {
    var cur = parmAr[i].split('=');
    var key = cur[0];
    var val = cur[1];
    parm[key] = val;
  }
  return parm[searchKey];
}