Re: Performance: While or For loop

On 3/22/07, Jon Anderson <janderson@gamingsolutions.ca> wrote:

Your test isn't exactly fair. The for loop has no statements in it, and the while loop has one. Your tests show while as approx 7% faster, while a modified test shows an approximate 30% speed improvement: Do this: for ($i=0;$i<10000000;$i++) {} v.s.: $i = 0; while ($i++ < 10000000) {} The above while loop is 30% faster than the for. A little teaking on the for loop, it's faster still:

I was comparing the way people normal use while and for. But this does confirms what i said, while is faster.

for ($i=10000000;$i--;) {} A little tweaking on the while, and it's faster yet: $i = 10000000; while ($i--) {} The last while loop is around 60% faster on my hardware than the first for loop. jon Tijnema ! wrote: On 3/22/07, Jake McHenry <linux@nittanytravel.com> wrote:

does this help? http://www.php.lt/benchmark/phpbench.php Jake

Well, there wasn't a test between For and While, so i did it myself, and i'm quite confused about the result. I let PHP count from 0 to 100000000 on my 1ghz AMD Athlon. While did it in a average time of 55 seconds. For did it in a average time of 59 seconds. It's not a big difference, if you see what number it needs to go to, but there is a difference. code used: <?php set_time_limit(100000); echo date("H:i:s"); for($i = 0; $i < 100000000;$i++) { } echo date("H:i:s"); $x = 0; while($x < 100000000) {

    $x++;

} echo date("H:i:s"); ?> So, use while loops instead of for loops ;) Tijnema ps. I also did the while loop before the for loop, doesn't matter.

-----Original Message----- From: Tijnema ! [mailto:tijnema@gmail.com] Sent: Thursday, March 22, 2007 4:38 PM To: PHP Subject: [PHP] Performance: While or For loop Hi, Does somebody has benchmarks of what is faster, while or for loop? Thanks, Tijnema -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.17/730 - Release Date: 3/22/2007 7:44 AM

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