operator strange behaviour
| From: | Hodicska Gergely | Date: | Sat, 30 Oct 2004 18:45:07 +0000 |
| Subject: | operator strange behaviour | ||
| Groups: | php.internals | ||
| Request: | Send a blank email to internals+get-13634@lists.php.net to get a copy of this message | ||
Hi!
I tried to get answer on the general list, but I didn't get.
I have a little example, which generate strange output.
$a = 0;
$b = 1;
if ($a = 1 && $b = 0) {
echo 'true ';
var_dump($a);
var_dump($b);
} else {
echo 'false ';
var_dump($a);
var_dump($b);
}
Runing this we get: "flase bool(false) int(0)"
After the precedence table the first step should be evaluating the &&, and we get something like this: $a = false = 0, which should generate an error, while there isn't an "lvalue" on the left side of the =.
But doesn't this happen. It seems, that the evaluation of the first = came before evaluating the &&.
Can someone exactly explain how PHP process this condition?
THX in advance,
Felho