Create all possible combinations from a dictionary

combinator.js

// create combination from a dictionary
function combination(dictionary, length, depth, input, output) {
    // check if this is the original call and instantiate the helpers
    if (!depth) {
        output = [];
        input = '';
        depth = 0;
    }

    // loop through the dictionary to create combinations
    dictionary.forEach(function(element) {
        if (depth == length - 1) {
            output.push(input + element);
        } else {
            combination(dictionary, length, depth + 1, input + element, output);
        }
    });

    // return value from original function call
    if (!depth)
        return output;

    // return to exit from recursive function call
    return;
}

// dictionary to create combinations from
var dictionary = ['a', 'b', 'c', 'd', 'e', 'f', 'g'];

// all combinations with 4 letters
var comb = combination(dictionary, 2);