On Sun, 11 Dec 2005, Octavian Rasnita wrote:
> Here is the test script:
>
> for(1 .. 50000000) {
> $i += 1;
> #$i = 1;
> #$i++;
> }
> print times();
>
> For $i += 1: 11.9210.03100
>
> For $i = 1: 11.6250.01500
>
> For $i++: 9.2960.03100
>
> So, $i=1 takes 25.05% more time to run than $i++ and $i+=1 takes 28.24% more
> time than $i++.
>
> I have made the test for more times, and the results were almost the same.
Sorry, I'm confused. These appear to do three different things.
With
$i += 1
the $i variable is declared once, then assigned 1 more 50_000_000 times.
With
$i = 1
the $i variable is assigned 1, 50_000_000 times.
With
$i++
the $i variable is incremented 50_000_000 times.
It looks like the assignment is the bottleneck. After that, it looks
like += is slightly slower because it has to look up and assign the
value each time, while the other version is assigning a constant and so
has been optimized at compile time.
But that's mainly a guess...
--
Chris Devers
tìçÎÆgº
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