Simple Memoization Example in JavaScriopt

memoization.js

var fibo = (function () {  
  var memo = {};
  function fi(n) {
    if (n < 0) { return -1 } else {
      var value = (n in memo) ? memo[n] : (!n || n === 1) ? 1 : fi(n - 1) + fi(n - 2);
      memo[n] = value;
      return value;
    }
  }
  return fi;
})();