no-jquery-combinations.js

/**
 * @author BigAB
 */
function combinations(arrayOfArrays) {
	if (Object.prototype.toString.call(arrayOfArrays) !== '[object Array]') {
		throw new Error("combinations method was passed a non-array argument");
	}
	
	var combinations = [],
		comboKeys = [],
		numOfCombos = arrayOfArrays.length ? 1 : 0,
		arrayOfArraysLength = arrayOfArrays.length;
	
	for(var n = 0; n < arrayOfArraysLength; ++n) {
		if(Object.prototype.toString.call(arrayOfArrays[n]) !== '[object Array]') {
			throw new Error("combinations method was passed a non-array argument");
		}
		numOfCombos = numOfCombos*arrayOfArrays[n].length;
	}
	
	for(var x = 0; x < numOfCombos; ++x) {
		var carry = x,
			comboKeys = [],
			combo = [];
		
		for(var i = 0; i < arrayOfArraysLength; ++i) {
			comboKeys[i] = carry % arrayOfArrays[i].length;
			carry = Math.floor(carry / arrayOfArrays[i].length);
		}
		for(var i = 0; i < comboKeys.length; ++i) {
			combo.push(arrayOfArrays[i][comboKeys[i]]);
		}
		combinations.push(combo);
	}
	
	return combinations;
}