[thelist] stupid PHP question

[Nan Harbison]

Hello All,

I have this function $array is a two dimensional array being retrieved from
a table):

   foreach ($array as $row)
   {
     $row_count = is_array($row) ? count($row) : 0;
     if ($row_count > $max_cols)
     {
        $max_cols = $row_count;
     }
   }

What I don't understand is the syntax of this line:

	$row_count = is_array($row) ? count($row) : 0;

I have spent hours looking through my PHP books, but can't find it. Can
someone please explain what the question mark is doing? And the count($row)
: 0?

Sorry, I know this is a dumb question.
TIA,
Nan