RE: [PHP] Performance and Function Calls
| From: | Don Read | Date: | Sun, 16 Mar 2003 04:25:29 +0000 |
| Subject: | RE: [PHP] Performance and Function Calls | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-139825@lists.php.net to get a copy of this message | ||
On 15-Mar-2003 CF High wrote:
> Hey all.
>
> Quick question:
>
> If I have a function that, say, prints out the months in a year, and I
> call
> that function within a 10 cycle loop, which of the following is faster:
>
> 1) Have function months() return months as a string; set var
> string_months = months() outside of the loop; then echo string_months
> within
> the loop
>
> -- OR
>
> 2) Just call months() for each iteration through the loop
>
> I'm not sure how PHP interprets option number 1.
>
> Guidance for the clueless much appreciated...........
>
Easy enuff to test:
<?php
function getmicrotime(){
list($usec, $sec) = explode(" ",microtime());
return ((float)$usec + (float)$sec);
}
$time_start = getmicrotime();
for ($m=1; $m <11; $m++) {
echo date('F', strtotime("2003-$m-1")), '<br>';
}
echo '<P>A: ', getmicrotime() - $time_start , '<P>';
$time_start = getmicrotime();
for ($m=1; $m <11; $m++) {
$str[]=date('F', strtotime("2003-$m-1"));
}
echo implode('<br>',$str);
echo '<P>B: ', getmicrotime() - $time_start , '<P>';
unset($str);
$time_start = getmicrotime();
for ($m=1; $m <11; $m++) {
$str[]=date('F', strtotime("2003-$m-1"));
}
while (list(,$v)= each($str)) {
echo $v, '<br>';
}
echo '<P>C: ', getmicrotime() - $time_start , '<P>';
?>
On my machine I get numbers like:
A: 0.000907063484192
B: 0.000651001930237
C: 0.000686049461365
The function call within the loop is slower (contrary to what I
expected), the real question is how much effort do you want to expend to
save 2-3 micro-seconds?
Regards,
--
Don Read dread@texas.net
-- It's always darkest before the dawn. So if you are going to
steal the neighbor's newspaper, that's the time to do it.