I use a Javascript hash object to store a set of numerical counters, set up like this [this is greatly simplified]:

var myHash = {
    A: 0,
    B: 0,
    C: 0
};

Is there a way to make other keys, ones not explicitly in myHash, map to keys that are? For instance, I'd like [again, this is simplified]:

myHash['A_prime']++; // or myHash.A_prime++;

to be exactly equivalent to

myHash['A']++; // or myHash.A++;

e.g. incrementing the value found at the key A, not A_prime.