Using `window.location.hash.includes` throws “Object doesn't support property or method 'includes'” in IE11

According to the MDN reference page, includes is not supported on Internet Explorer. The simplest alternative is to use indexOf, like this:

if(window.location.hash.indexOf("?") >= 0) {
    ...
}

IE11 does implement String.prototype.includes so why not using the official Polyfill?

  if (!String.prototype.includes) {
    String.prototype.includes = function(search, start) {
      if (typeof start !== 'number') {
        start = 0;
      }

      if (start + search.length > this.length) {
        return false;
      } else {
        return this.indexOf(search, start) !== -1;
      }
    };
  }

Source: polyfill source

Adding import 'core-js/es7/array'; to my polyfill.ts fixed the issue for me.