JavaScript String/URL methods

string-methods.js

if (typeof String.prototype.startsWith != 'function') {
  String.prototype.startsWith = function (str){
    return this.slice(0, str.length) == str;
  };
}

if (typeof String.prototype.toURL != 'function') {
  String.prototype.toURL = function () {
    var parser = document.createElement('a');
        parser.href = this;
    return parser;
  };
}

/* IE Doesn't have window.location.origin by default, this snippet fixes that.
 * @link http://tosbourn.com/a-fix-for-window-location-origin-in-internet-explorer/
 */
if (!window.location.origin) {
  window.location.origin = window.location.protocol + "//" + window.location.hostname + (window.location.port ? ':' + window.location.port: '');
}

if (typeof String.prototype.isInternalURL != 'function') {
  String.prototype.isInternalURL = function() {
    var parser = this.toURL(),
        href = parser.href,
        location = window.location.origin;
    return href.startsWith(location);
  };
}

if (typeof String.prototype.URLHasHash != 'function') {
  String.prototype.URLHasHash = function () {
    var parser = this.toURL(),
        hash = parser.hash;
    return ( hash.length > 0 );
  };
}