40 Tips for optimizing your php Code

[sde]

I'm not sure how accurate his testing was but it's a great read none the less.

reinholdweber.com

[Belisarius]

Damn - I'm doing something on the order of 90% of the slow things he mentions. I didn't think "require_once" would be expensive - shouldn't it just be like a hash-table lookup or something?

They did leave out the big one that I came across - is_dir() is a *really* expensive call. I still use it all over the place, but I try really hard to not use it in large loops.

[DJMaze]

#8: Use full paths in includes and requires, less time spent on resolving the OS paths.

This is wrong. In PHP5 when you use full paths each directory gets checked for permissions.
It makes any disk access function 4 times slower then in PHP 4 (per request around 0.0016 seconds).

#9: $_SERVER[’REQUEST_TIME’]
This is inaccurate and does not contain the script execution but the REQUEST

#17 $row[’id’] is 7 times faster than $row[id]
That's because $row[id] is bad code. Use error_reporting(E_ALL) and you will notice that PHP tries to find a constant named id.

The rest is rather true, yet some points sound like being the same as a previous point.

[DJMaze]

Funny, i've just tested something with a fellow coder.
It seems using ternary operators in PHP is slower then binary if {} else {}

PHP Code:

<?php

$time = microtime(true);
for ($i=0; $i<1000000; ++$i)
{
    $foo = ($i%2==0) ? 0 : 1;
}
$time = microtime(true)-$time;
echo 'ternary in: '.round($time,4).' seconds<br>';

$time = microtime(true);
for ($i=0; $i<1000000; ++$i)
{
    if ($i%2==0)
    {
        $foo = 0;
    }
    else
    {
        $foo = 1;
    }
}
$time = microtime(true)-$time;
echo 'if..else.. in: '.round($time,4).' seconds<br>';

Result P4 2.54

ternary in: 0.5543 seconds
if..else.. in: 0.5709 seconds

Result P2

ternary in: 3.4309 seconds
if..else.. in: 2.7495 seconds

It's hardly noticeable though since how often do you use the ternary?

[sde]

ternary in: 0.3621 seconds
if..else.. in: 0.3642 seconds

this is what i got on my laptop intel core duo with php5