Get cookies JavaScript

cookies.js

/*
 * Get Cookie
 * Return cookie value by key
 *
 * @author Mozilla Foundation
 * @url https://developer.mozilla.org/en-US/docs/Web/API/document/cookie
 *
 * @param {string} Cookie's name to lookup
 * @return {string} Cookie's value
 */
function getCookie (name) {
  var cookieValue = null;

  if (!name) { return null; }
  return decodeURIComponent(
    document.cookie.replace(new RegExp("(?:(?:^|.*;)\\s*" +
    encodeURIComponent(name).replace(/[\-\.\+\*]/g, "\\$&") +
    "\\s*\\=\\s*([^;]*).*$)|^.*$"), "$1")) || null;
}