array to keep track new and used?

[Lauri26]

I scan used schoolbook barcodes into a textarea. 😃 If I scan a "33333" barcode, that means the Previous book is to be graded as NEW. :eek:

My problem is not getting PHP to read the textarea (easy! I know how to use "explode"), but getting PHP to list a unique ISBN number with BOTH a "new" and "used" grading. Here's an example of scanned Textarea input: :queasy:

2222222222
0132456987
33333
2456878965
2222222222
33333

Okay, you'll notice that I scanned ISBN 2222222222 twice -- once as a Used book, and once as a New book. Here's my PHP page desired Result:
2222222222: 1u, 1n
0132456987: 0u, 1n
2456878965: 1u, 0n

So, to get the scanned ISBNs into an array, I use explode ($arr = explode("\n",$textareaData)). Followed by array_unique.

But my Knowledge of PHP is very, very weak in building arrays.

Would someone please give me the line(s) of code?

[Weedpacket]

You could reverse the array (or just read through it in reverse order). Then go through each element of the array in (reversed) order, so that when you see '33333' you know that the next see you read will be that of a used barcode.

[sneakyimp]

Elaborating on weedpacket's suggestion, If you take the contents of the array using [man]explode[/man] then you can keep using [man]array_pop[/man] to remove the last element in the array.

You'll just need a loop to pop off all the elements one by one and then some vars to keep track of whether you've just seen a 33333 or a book iSBN number.