note 96198 modified in function.in-array by danbrown

If you're working with very large 2 dimensional arrays (eg 20,000+ elements) it's much faster to do this... <?php $needle = 'test for this'; $flipped_haystack = array_flip($haystack); if ( isset($flipped_haystack[$needle]) ) { print "Yes it's there!"; } ?> I had a script that went from 30+ seconds down to 2 seconds (when hunting through a 50,000 element array 50,000 times). Remember to only flip it once at the beginning of your code though! --was-- If you're working with very large 2 dimensional arrays (eg 20,000+ elements) it's much faster to do this... $needle = 'test for this'; $flipped_haystack = array_flip($haystack); if ( isset($flipped_haystack[$needle]) ) { print "Yes it's there!"; } I had a script that went from 30+ seconds down to 2 seconds (when hunting through a 50,000 element array 50,000 times). Remember to only flip it once at the beginning of your code though! http://php.net/manual/en/function.in-array.php