note 89886 added to function.defined

Before using defined() have a look at the following benchmarks: true 0.65ms $true 0.69ms (1) $config['true'] 0.87ms TRUE_CONST 1.28ms (2) true 0.65ms defined('TRUE_CONST') 2.06ms (3) defined('UNDEF_CONST') 12.34ms (4) isset($config['def_key']) 0.91ms (5) isset($config['undef_key']) 0.79ms isset($empty_hash[$good_key]) 0.78ms isset($small_hash[$good_key]) 0.86ms isset($big_hash[$good_key]) 0.89ms isset($small_hash[$bad_key]) 0.78ms isset($big_hash[$bad_key]) 0.80ms PHP Version 5.2.6, Apache 2.0, Windows XP Each statement was executed 1000 times and while a 12ms overhead on 1000 calls isn't going to have the end users tearing their hair out, it does throw up some interesting results when comparing to if(true): 1) if($true) was virtually identical 2) if(TRUE_CONST) was almost twice as slow - I guess that the substitution isn't done at compile time (I had to double check this one!) 3) defined() is 3 times slower if the constant exists 4) defined() is 19 TIMES SLOWER if the constant doesn't exist! 5) isset() is remarkably efficient regardless of what you throw at it (great news for anyone implementing array driven event systems - me!) May want to avoid if(defined('DEBUG'))... ---- Server IP: 117.104.160.194 Probable Submitter: 121.214.143.34 ---- Manual Page -- http://www.php.net/manual/en/function.defined.php Edit -- https://master.php.net/note/edit/89886 Del: integrated -- https://master.php.net/note/delete/89886/integrated Del: useless -- https://master.php.net/note/delete/89886/useless Del: bad code -- https://master.php.net/note/delete/89886/bad+code Del: spam -- https://master.php.net/note/delete/89886/spam Del: non-english -- https://master.php.net/note/delete/89886/non-english Del: in docs -- https://master.php.net/note/delete/89886/in+docs Del: other reasons-- https://master.php.net/note/delete/89886 Reject -- https://master.php.net/note/reject/89886 Search -- https://master.php.net/manage/user-notes.php