Getting URL Params in Javascript (Vanilla)

getUrlParamsVanilla.js

// *** 
// This is the function that does the work, put it at the top of your JS file (at least above where you are going to use it). 
//  Then you can forget about it. Don't worry about the 'exclude' part.
// ***
// START COPY AND PASTE
(function () {
console.log("Gist is running...");
var getUrlParams = function(exclude){
  var str = window.location.search;
  if (str === "" || str === "?" || str === "#") return {};
      exclude = exclude ? exclude : [];
      exclude = exclude instanceof Array ? exclude : [];
      var p = str.indexOf("?") === 0 ? str.substring(1).split("&") : str.split("&");
      var temp,
        len = p.length,
        result = {};

      for (var i = 0; i < len; i++) {
        temp = p[i].split("=");
        if (exclude.indexOf(temp[0]) === -1) {
          result[temp[0]] = decodeURIComponent(temp[1]);
        }
      }

      return result;
}
//  Example HTML
// <input id='my-hidden-input' type='hidden' val='' />
var params = getUrlParams();
console.log("These are the params it captured:");
console.log(params);
// params looks like this
// {
//  source: "wcw"
// };
  
// Now this puts source property in to hidden input
document.getElementById('my-hidden-input').value = params.source;
console.log("Should have worked now...");
console.log("value of the input is: " + document.getElementById('my-hidden-input').value);
})();

// END COPY AND PASTE