note 71899 added to language.types.integer

Be careful when using integer conversion to test something to see if it evaluates to a positive integer or not. You might get unexpected behaviour. To wit: <?php error_reporting(E_ALL); require_once 'Date.php'; $date = new Date(); print "\$date is an instance of " . get_class($date) . "\n"; $date += 0; print "\$date is now $date\n"; var_dump($date); $foo = new foo(); print "\$foo is an instance of " . get_class($foo) . "\n"; $foo += 0; print "\$foo is now $foo\n"; var_dump($foo); class foo { var $bar = 0; var $baz = "la lal la"; var $bak; function foo() { $bak = 3.14159; } } ?> After the integer conversion, you might expect both $foo and $date to evaluate to 0. However, this is not the case: $date is an instance of Date Notice: Object of class Date could not be converted to int in /home/kpeters/work/sketches/ObjectSketch.php on line 7 $date is now 1 int(1) $foo is an instance of foo Notice: Object of class foo could not be converted to int in /home/kpeters/work/sketches/ObjectSketch.php on line 13 $foo is now 1 int(1) This is because the objects are first converted to boolean before being converted to int. ---- Server IP: 64.71.164.2 Probable Submitter: 68.58.250.171 ---- Manual Page -- http://www.php.net/manual/en/language.types.integer.php Edit -- https://master.php.net/note/edit/71899 Del: integrated -- https://master.php.net/note/delete/71899/integrated Del: useless -- https://master.php.net/note/delete/71899/useless Del: bad code -- https://master.php.net/note/delete/71899/bad+code Del: spam -- https://master.php.net/note/delete/71899/spam Del: non-english -- https://master.php.net/note/delete/71899/non-english Del: in docs -- https://master.php.net/note/delete/71899/in+docs Del: other reasons-- https://master.php.net/note/delete/71899 Reject -- https://master.php.net/note/reject/71899 Search -- https://master.php.net/manage/user-notes.php