I am looking for comparisons between parallel arrays, 2d arrays, and an array with objects for this problem:

I am storing 100 item numbers and their available quantities. I will want to sort the numbers and combine item numbers that are the same.

What data structure would you use to solve this problem? I do not need code examples or instructions on how do build anything. I am looking for discussion on what is better/faster, not code.

Thanks

Rule of thumb, list (or other collection/datastructure) of objects is preferred in OOP.

Parallel arrays are almost always a bad idea, especially if you're sorting n arrays based on another's index.

2D arrays have no place here. one obvious reason is the datatype restriction. what if item numbers aren't necessarily integers (eg: UPC)? and the more columns you add, the more likely you'll need different datatypes. But more importantly, you shouldn't be associating different attributes in an array like that unless it's necessary.

as for "faster", it's irrelevant for an example like this.

This post was edited by carteblanche on Jan 5 2014 03:14pm

multi dimension array, look into PHP's usort

If the only thing you want to associate with each item number are the quantities, then you should probably go with some type of associative array where the key is the item number and the value is the quantity. If you're really worried about performance, maybe a hash table is the way to go (I think that's generally the default associative array type?). This makes looking up an item's quantity much faster, but the size of the hash table structure is much larger than a regular array or 2d array.

If you have more than just quantities with the items, you couldl do an associative array where the key is the item number and the value is the item object (with quantity and other attributes).

This post was edited by Kronosaurus on Jan 11 2014 11:20am

When I said "better/faster" I was talking about coding time and simplicity to modify and understand quickly. With only 100 items, performance is irrelevant as carteblanche said.