old_contents: String.prototype.hasVowels = function() {
    var vowels = new RegExp('[aeiou]', 'i');
    return vowels.test(this) ? true : false;
  };
  
  String.prototype.toUpper = function () {
    var newString = '';
    var upper = new RegExp('[a-z]');
    for (var x = 0; x < this.length; x++) {
      upper.test(this[x]) ?
      newString += String.fromCharCode((this.charCodeAt(x)) - 32) :
      newString += this[x];
    }
    return newString;
  };
  
  String.prototype.toLower = function () {
    var newString = '';
    var upper = new RegExp('[A-Z]');
    for (var x = 0; x < this.length; x++) {
      upper.test(this[x]) ?
      newString += String.fromCharCode((this.charCodeAt(x)) + 32) :
      newString += this[x];
    }
    return newString;
  };
  
  String.prototype.ucFirst = function () {
    return [this.charAt(0).toUpper(), this.slice(1)].join('');
  };
  
  String.prototype.isQuestion = function () {
    var quest = new RegExp(/\?$/);
    return quest.test(this) ? true : false;
  };
  
  String.prototype.words = function () {
    var splitter = new RegExp(/\W+/);
    return this.split(splitter);
  };
  
  String.prototype.wordCount = function () {
    var count = 0;
    this.words().forEach(() => {
      count += 1;
  
    });
  
    return count;
  };
  
  String.prototype.toCurrency = function () {
    return  (parseFloat(this).toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, '$1,')).toString();
  };
  
  String.prototype.fromCurrency = function () {
    return Number(this.replace(/\,/,''));
  
  };
  
new_contents: String.prototype.hasVowels = function() {
    var vowels = new RegExp('[aeiou]', 'i');
    return vowels.test(this) ? true : false;
  };
  
  String.prototype.toUpper = function () {
    var newString = '';
    var upper = new RegExp('[a-z]');
    for (var x = 0; x < this.length; x++) {
      upper.test(this[x]) ?
      newString += String.fromCharCode((this.charCodeAt(x)) - 32) :
      newString += this[x];
    }
    return newString;
  };
  
  String.prototype.toLower = function () {
    var newString = '';
    var upper = new RegExp('[A-Z]');
    for (var x = 0; x < this.length; x++) {
      upper.test(this[x]) ?
      newString += String.fromCharCode((this.charCodeAt(x)) + 32) :
      newString += this[x];
    }
    return newString;
  };
  
  String.prototype.ucFirst = function () {
    return [this.charAt(0).toUpper(), this.slice(1)].join('');
  };
  
  String.prototype.isQuestion = function () {
    var quest = new RegExp(/\?$/);
    return quest.test(this) ? true : false;
  };
  
  String.prototype.words = function () {
    var splitter = new RegExp(/\W+/);
    return this.split(splitter);
  };
  
  String.prototype.wordCount = function () {
    var count = 0;
    this.words().forEach(() => {
      count += 1;
  
    });
  
    return count;
  };
  
  String.prototype.toCurrency = function () {
    return (parseFloat(this).toFixed(2).replace(/(\d)(?=(\d{3})+\.)/g, '$1,'))
    .toString();
  };
  
  String.prototype.fromCurrency = function () {
    return Number(this.replace(/\,/,''));
  
  };
  
subject: Add fromCurrency function