Factorial functions, one recursive and one iterative Wanted to see if there were any significant differences in performance. http://jsperf.com/factorial-recursive-v-iterative

gistfile1.js

var factorialRecursive = (function () {
	// 0! = 1 just 'cause
	var factorials = [ 1 ];

	return function fFactorial( n ) {
		if ( n < 0 ) {
			// negative n! not defined
			return null;
		} else if ( factorials[ n ] ) {
			return factorials[ n ];
		} else {
			factorials[ n ] = n * fFactorial( n - 1 );
			return factorials[ n ];
		}
	};
}());

var factorialIterative = (function () {
	// 0! = 1 just 'cause
	var factorials = [ 1 ];

	return function ( n ) {
		var j = factorials.length;

		if ( n < 0 ) {
			// negative n! not defined
			return null;
		} else {
			while( j <= n ) {
				factorials[ j ] = j * factorials[ j - 1 ];
				j += 1;
			}
			return factorials[ n ];
		}
	};
}());