unsetting $tmp var in a foreach loop ?

[ftrudeau]

this might a stupid question, and I must admit I dont know how PHP works exactly when assigning data to a variable, either a string, an int or an array.

assume this :

foreach ($redirs['0'] as $key => $value) {
     $tmp['years'] = trim($redirs['1'][$key]);
     $tmp['expiration'] = trim($redirs['2'][$key]);
     $tmp['source'] = trim($redirs['3'][$key]);
     $tmp['destination'] = trim($redirs['4'][$key]);
     array_push($redirections, $tmp);
}

In this example, im building an array of redirections that our users have set. The $redirs array is coming from a preg_match_all on a plain text file.

Anywho, my question is, would I make PHP use memory more wiselly if I resetted the $tmp array in the foreach loop, like this :

foreach ($redirs['0'] as $key => $value) {
     $tmp['years'] = trim($redirs['1'][$key]);
     $tmp['expiration'] = trim($redirs['2'][$key]);
     $tmp['source'] = trim($redirs['3'][$key]);
     $tmp['destination'] = trim($redirs['4'][$key]);
     array_push($redirections, $tmp);
     unset($tmp);
}

Would that make the script run more rapidelly ? Or does PHP auto-magically frees memory used by the last use of $tmp when im assigning new data to it ?

Thanks for any pointers on this one =)

[Weedpacket]

PHP handles memory management, freeing up data as soon as it's no longer accessible (like when the variable containing it has gone out of scope or been set to contain something else).
There's an article on PHP's memory management at Zend.