Create all the N combinations of a characters

combinations.js

/**
 * Created by Usuario on 03/10/2015.
 */
var available_characters = ["a","b"];

console.log(combinations(available_characters,5));

function combinations(available_characters,count_char)
{
    var acum_results = {combs : []};
    available_characters.forEach(function (el,i,array) {
        next_comb(el,available_characters,count_char,acum_results);
    });
    return acum_results.combs;
}

function next_comb(string,available_characters,count_char,acum_results)
{
    if (string.length == count_char)
    {
        return 0;
    }
    available_characters.forEach(function (el,i,array) {
        var str = string+""+el;
        acum_results.combs.push(str);
        next_comb(str,available_characters,count_char,acum_results);
    });
}