Get query string values in ES6.

class GetParams {
  constructor(name) {
    this.name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
  }

  run() {
    const regex   = new RegExp("[\\?&]" + this.name + "=([^&#]*)"),
          results = regex.exec(location.search);

    return results === null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
  }
}
  
const getParams = new GetParams('hash'),
      hash = getParams.run();

• url - How can I get query string values in JavaScript? - Stack Overflow