Count Similar Array Keys

Question

I have a POST request coming to one of my pages, here is a small segment:

[shipCountry] => United States
[status] => Accepted
[sku1] => test
[product1] => Test Product
[quantity1] => 1
[price1] => 0.00

This request can be any size, and each products name and quantity's key would come across as "productN" and "quantityN", where N is an integer, starting from 1.

I would like to be able to count how many unique keys match the format above, which would give me a count of how many products were ordered (a number which is not explicitly given in the request).

What's the best way to do this in PHP?

Answer 1

Well, if you know that every product will have a corresponding array key matching "productN", you could do this:

$productKeyCount = count(preg_grep("/^product(\d)+$/",array_keys($_POST)));

preg_grep() works well on arrays for that kind of thing.

Answer 2

What Gumbo meant with his "use array instead" comment is the following:

In your HTML-form use this:

<input type="text" name="quantity[]" />

and $_POST['quantity'] will then be an array of all containing all of your quantities.

If you need to supply an id you can also do this:

<input type="text" name="quantity[0]" />

$_POST['quantity][0] will then hold the corresponding quantity.