A PHP Regex Query

Question

I've only just been trying to teach myself how to use regular expressions so sorry if this seems trivial to some.

I'm making a little crib script. It uses a standard deck of playing cards and I'm using CDHS (clubs, diamonds, hearts, spades) for suits and A2..9TJQK (ace, 2...9, 10, jack, queen, king) for the ranks.

I have variable $hand which is an even-length string of cards. For example, S2HA3D would be the 2 of spades, ace of hearts and 3 of diamonds respectively. Note the suit and rank can be either way round.

I'm using:

preg_match_all("/[2-9ATJQK][CDHS]|[CDHS][2-9ATJQK]/i", $hand, $result);

to find all the cards but this returns suits and ranks in the order found.

My question is how can I make the result give the rank first for each card, regardless of the order given. I hope I've worded this clearly.

Answer 1

I don't think you can do that with preg_match only.

This function is meant to match strings, not manipulate them. You can, however, do a preg_replace in a second pass:

preg_match_all("/[2-9ATJQK][CDHS]|[CDHS][2-9ATJQK]/i", $hand, $rawResult);
$normalisedResult = preg_replace('/([CDHS])([2-9ATJQK])/i', "$2$1", $rawResult[0]);

In case you wonder, $1 and $2 are backreferences to the groups identified by the parenthesis in the first argument of preg_replace().