I had the feeling I finally need to solve this issue! :)

EvenOrOdd.js

// Found this awesome way in Java code once and had
// the strong feeling I need to port it to Javascript
// for the sake of all NodeJS developers!
var EvenOrOdd = function() {
  function EvenOrOdd() {}
  EvenOrOdd.prototype.isEven = function(value) {
    var even = "02468";
    var v = String(value);
    var w = v.charAt(v.length - 1);
    return even.indexOf(w) != -1;
  }
  EvenOrOdd.prototype.isOdd = function(value) {
      return !isEven(value);
  }
  return new EvenOrOdd;
}
module.exports.EvenOrOdd = new EvenOrOdd();

(function() {
  var test = new EvenOrOdd();
  console.log(test.isEven(124));
})();