utils.js

(function() {
  /**
   * Pad the left-side of this string with a 'padStr'
   *
   * @param padStr: string that will be padded
   * @param length: number of characters to return
   * @returns {String}
   */
  String.prototype.lpad = function(padStr, length) {
      var str = this;
      while (str.length < length)
          str = padStr + str;
      return str;
  }
  
  /**
   * Pad the right-side of this string with a 'padStr'
   *
   * @param padStr: string that will be padded
   * @param length: number of characters to return
   * @returns {String}
   */
  String.prototype.rpad = function(padStr, length) {
      var str = this;
      while (str.length < length)
          str = str + padStr;
      return str;
  }

  /**
   * Convert this number to a binary string with a
   *
   * @param minLength: minimum length for the binary string (default 8)
   * @returns {String}
   */
  Number.prototype.toBinary = function(minLength) {
      minLength = minLength == null? 8: minLength; // default
      return parseInt(this).toString(2).lpad("0", minLength);
  };
  
  /**
   * Convert this number to binary array
   *
   * @param minLength: minimum length for the binary array (default 8)
   * @returns {Array[int]}
   */
  Number.prototype.toBinaryArray = function(minLength) {
      return this.toBinary(minLength).split("").map(function(str){
          return parseInt(str);
      });
  };
})();