JavaScript optimization example using console.time

javascript-optimization-example.js

/**
 * @link http://adripofjavascript.com
 */

// Example 1
(function(console) {
  function factoral(num) {
    if (num < 0) throw new Error('Bad input!');
    if (num % 1 !== 0) throw new Error('That\'s NaN!');
    if (num === 0 || num === 1) return 1;
    return num * factoral(num - 1); 
  }

  console.time('foo');
  for(var i = 0; i < 100; i++) { factoral(20); }
  console.timeEnd('foo');
})(window.console);


// Example 2 - Optimized
(function(console) {
  function factoral(num) {
    if (num < 0) throw new Error('Bad input!');
    if (num % 1 !== 0) throw new Error('That\'s NaN!');
    if (num === 0 || num === 1) return 1;

    function inception(n) {
      if (n === 0 || n === 1) return 1;
      return n * inception(n - 1); 
    }
    return inception(num);    
  }

  console.time('bar');
  for(var i = 0; i < 100; i++) { factoral(20); }
  console.timeEnd('bar');
})(window.console);