note 95874 added to function.strpos

Dan Brown and I had a discussion on the PHP list about the speed difference between the popular three string searching techniques. He wrote a simple timing test, and I adapted it further. The end result is that all three are very close and not even noticeable for sets < 1M. Although, technically strpos() is about twice as fast (as the docs allude to above). Here it is for your own amusement and testing purposes. <?php for ($i = 0; $i < 1000000; $i++ ) $o[] = sprintf('%04d-%02d-%02d',rand(0000,9999),rand(00,99),rand(00,99)); #print_r($o); echo "array of ".number_format($i)."\n"; ################################################################### $now = microtime(true); for($i=0;$i<count($o);$i++) { if(preg_match('/^[0]{4,}\-/U',$o[$i])) { //echo "Offset #".$i." matches: ".$o[$i].PHP_EOL; } } $rank['preg_match'] = (microtime(true) - $now); ################################################################### $later = microtime(true); for($i=0;$i<count($o);$i++) { if(substr($o[$i],0,4) == "0000") { //echo "Offset #".$i." matches: ".$o[$i].PHP_EOL; } } $rank['substr'] = (microtime(true) - $later); ################################################################### $after = microtime(true); for($i=0;$i<count($o);$i++) { if(strpos($o[$i], '0000') === 0) { //echo "Offset #".$i." matches: ".$o[$i].PHP_EOL; } } $rank['strpos'] = (microtime(true) - $after); ################################################################### asort($rank); print_r($rank); ?> array of 10,000 Array ( [strpos] => 0.00766682624817 [substr] => 0.0116670131683 [preg_match] => 0.0124950408936 ) array of 100,000 Array ( [strpos] => 0.0817799568176 [substr] => 0.120522975922 [preg_match] => 0.125612974167 ) array of 1,000,000 Array ( [strpos] => 0.805890083313 [substr] => 1.19799995422 [preg_match] => 1.25615906715 ) I ran out of memory with more than 1M array elements. ---- Server IP: 208.69.120.55 Probable Submitter: 206.169.197.253 ---- Manual Page -- http://www.php.net/manual/en/function.strpos.php Edit -- https://master.php.net/note/edit/95874 Del: integrated -- https://master.php.net/note/delete/95874/integrated Del: useless -- https://master.php.net/note/delete/95874/useless Del: bad code -- https://master.php.net/note/delete/95874/bad+code Del: spam -- https://master.php.net/note/delete/95874/spam Del: non-english -- https://master.php.net/note/delete/95874/non-english Del: in docs -- https://master.php.net/note/delete/95874/in+docs Del: other reasons-- https://master.php.net/note/delete/95874 Reject -- https://master.php.net/note/reject/95874 Search -- https://master.php.net/manage/user-notes.php