Increment a string with letters?

Question

I need to increment a string from.. let\'s say aaa to zzz and write every incrementation in the console (is incrementation even a word?). It would go s

Answer 1

I just want to provide an alternative answer to @procrastinator's (since I can't comment on the answer because I don't have enough points on Stackoverflow). His answer seems like the most generic approach but I can't help and notice that after "z" comes "ba" when op expect it to be "aa". Also, this follows how Excel name it's columns.

Here is the code with corrections:

function s2n(s) {
    var pow, n = 0, i = 0;
    while (i++ < s.length) {
        pow = Math.pow(26, s.length - i);
        var charCode = s.charCodeAt(i - 1) - 96;
        n += charCode * pow;
    }
    return n;
}

function n2s(n) {
    var s = '';  
    var reduce = false;

    if (n === undefined) {
        n = 0;
    } else {
        n--;
    }
    while (n !== undefined) {
        s = String.fromCharCode(97 + n % 26) + s;
        n = Math.floor(n / 26);
        if (n === 0) {
            n = undefined;
        } else {
            n--;
        }
    }
    return s;
}

Instead of starting from 0, this will consider 1 to be "a", 26 to be "z", 27 to be "aa" and so on.