How efficient is define in PHP?

Question

C++ preprocessor #define is totally different.

Is the PHP define() any different than just creating a var?

define(\"SETTING         


        

Answer 1

php > $cat='';$f=microtime(1);$s='cowcow45';$i=9000;while ($i--){$cat.='plip'.$s.'cow';}echo microtime(1)-$f."\n";

0.00689506530762

php > $cat='';$f=microtime(1);define('s','cowcow45');$i=9000;while ($i--){$cat.='plip'.s.'cow';}echo microtime(1)-$f."\n";

0.00941896438599

This is repeatable with similar results. It looks to me like constants are a bit slower to define and/or use than variables.