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.
Assuming there aren't any valid string values in this hash, you could create your own mapping of keys to other keys, within the hash itself, and wrap the key/value pairs in your own function, as follows:
var hash = {
A: 0,
B: 0,
C: 0,
A_asdf: 'A',
B_asdf: 'B',
A_another: 'A'
}
function increment(key)
{
// iteratively find the real key
while (typeof(hash[key]) == 'string')
{
key = hash[key];
}
hash[key]++;
}
A way of solving this would be wrapping all values in an object, and use this object in several keys.
var myHash = {
A: {value: 0},
...
};
myHash['A_prime'] = myHash['A'];
myHash['A_prime'].value++;
I think you would be better off just writing a function to accomplish the incrementation of one hash array or multiple depending on what you are trying to accomplish. I may have not understood the question correctly but this is my solution.
var smallHash = {
A: 0,
B: 0,
C: 0,
A_prime:'A',
B_prime:'B',
C_prime:'C'
};
function incrementPrime(myHash,key)
{
letterKey = myHash[key];
myHash[letterKey]++;
}
incrementPrime(smallHash,'C_prime');
alert("C is now: "+smallHash['C']); // should return 1
You could act on the key, instead of the hash:
var myHash = {
A: 0,
B: 0,
C: 0
};
function incr(prop){
myHash[prop[0]]++;
}
incr('A');
incr('A_asdf');
The function incr could be anything else you want to apply to the hash.
As described, no. If you can change your keys to objects though you'd get closer:
var x = new Object();
var y = x;
myHash[x] = 1;
myHash[y]++; // should increment the value since y is x.
myHash object will end with a property named "[object Object]" because the [] property accessor operator will convert x and y to String.