Basic Question:

If I'm storying/modifying data, should I access elements of a file by index hard-coded index, i.e. targetFile.getElement(5); via a hardcoded identifier (internally translated into index), i.e. target.getElementWithID("Desired Element"), or with some intermediate DESIRED_ELEMENT = 5; ... target.getElement(DESIRED_ELEMENT), etc.

Background:

My program (c++) stores data in lots of different 'dataFile's. I also keep a list of all of the data-files in another file---a 'listFile'---which also stores some of each one's properties (see below, but i.e. what it's name is, how many lines of information it has etc.). There is an object which manages the data files and the list file, call it a 'fileKeeper'.

The entries of a listFile look something like:

filename , contents name , number of lines , some more numbers ...

Its definitely possible that I may add / remove fields from this list --- but in general, they'll stay static.

Right now, I have a constant string array which holds the identification of each element in each entry, something like:

const string fileKeeper::idKeys[] = { "FileName" , "Contents" , "NumLines" ... };
const int fileKeeper::idKeysNum = 6;   // 6 - for example

I'm trying to manage this stuff in 'good' programatic form. Thus, when I want to retrieve the number of lines in a file (for example), instead of having a method which just retrieves the '3'rd element... Instead I do something like:

string desiredID = "NumLines";
int desiredIndex = indexForID(desiredID);
string desiredElement = elementForIndex(desiredIndex);

where the function indexForID() goes through the entries of idKeys until it finds desiredID then returns the index it corresponds to. And elementForIndex(index) actually goes into the listFile to retrieve the index'th element of the comma-delimited string.

Problem:

This still seems pretty ugly / poor-form. Is there a way I should be doing this? If not, what are some general ways in which this is usually done?

Thanks!