The most rudimentary and slow way to do this is to use coarrays. Possibly both arrays would be in a single struct to keep them together, and possibly ease use.
One array would be of type char *, with each entry being a null-terminated C "string". The other array would be whichever type you'd like to "map" to. It would be the same length as the char * array.
A lookup would be two steps. The first would be a linear search for a string match. If found, the same index is used to retrieve the value from the second array.
This will be abysmally slow. To improve it, there are plenty of choices. One is to make a struct with a key and value element, and keep an array of those, and sort it by key. Once you have this, you perform a binary search, which will be much quicker than a linear search. Adding elements later will be very slow unless you get awfully clever and keep your backing array sparse and use a clever scheme to avoid the unused spots during your search.
Next is using a hashing scheme to allow faster lookups. The details aren't fit for a quick summary here, but it comes down to performing an operation on the keys to more quickly determine its position in the backing array. This is the technique used in NSDictionary, Java's HashMap, etc.
What C provides you with is the basic building blocks. Every language that provides you with data structures built-in or in a standard library have had these created by others from similar building blocks.
-Lee
