JavaScript - Generating combinations from n arrays with m elements

Question

I\'m having trouble coming up with code to generate combinations from n number of arrays with m number of elements in them, in JavaScript. I\'ve seen similar questions about

Answer 1

Just for fun, here's a more functional variant of the solution in my first answer:

function cartesian() {
    var r = [], args = Array.from(arguments);
    args.reduceRight(function(cont, factor, i) {
        return function(arr) {
            for (var j=0, l=factor.length; j

Alternative, for full speed we can dynamically compile our own loops:

function cartesian() {
    return (cartesian.cache[arguments.length] || cartesian.compile(arguments.length)).apply(null, arguments);
}
cartesian.cache = [];
cartesian.compile = function compile(n) {
    var args = [],
        indent = "",
        up = "",
        down = "";
    for (var i=0; i