a little JavaScript kata inspired by Dr. Marcus du Sautoy's discussion of Euclid's "Greatest Common Divisor" algorithm.

Euclid.js

var Euclid = {};

Euclid.gcd = function greatestCommonDivisor( a, b) {

    "use strict";

    var lilNum, bigNum, modulo;

    lilNum = Math.min( a, b);
    bigNum = Math.max( a, b);

    modulo = bigNum % lilNum;

    if (modulo !== 0) {
        return this.gcd(modulo, lilNum);
    }
    else {
        return lilNum;
    }
}

I don't like recursive functions. I always seem to find a way to "blow the stack" when I write them, but this one went surprisingly well.