optimize FileLocator autoloader : use foreach instead of for with count when possible

[samsonasik]

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[michalsn]

Sorry for the silly question but is foreach faster than for? Or this is just for readability purposes?

[samsonasik]

previously, with for, it need to run count() first, while direct foreach is enough.

[michalsn]

Yes, I understand this part, but isn't foreach slower than for?

[samsonasik]

direct foreach is faster. Example benchmark about for with count vs direct foreach : https://coderwall.com/p/il1tog/php-for-vs-foreach-benchmark

[samsonasik]

➜  ~ curl https://gist.githubusercontent.com/nodesocket/3909074/raw/80e1bd3612b2b1680d6d519c8fd53bb79435e9de/gistfile1.php -o benchmark-for-vs-foreach.php

➜  ~ php benchmark-for-vs-foreach.php 
For took: 2.862ms
For with count() took: 3.643ms
Foreach took: 1.489ms

[michalsn]

I get quite different results to be honest

For took: 0.128ms
For with count() took: 0.175ms
Foreach took: 0.162ms

Also checked it on sandbox: https://phpsandbox.io/n/red-king-pnbr

[samsonasik]

The code that I updated previosly uses count+for, so foreach still win

[michalsn]

Not really. "For with count()" is when we use count() inside for() loop, like:

for($i = 0; $i < count($elements); $i++)

and it's not the case here.

[samsonasik]

The benchmark code need update to associative array and run the code inside loop, I updated the benchmark code at https://phpsandbox.io/n/super-fog-72g7 with place assign count() to variable first, but execute it. I got it:

For took: 0.066ms
For with count() took: 0.167ms
Foreach took: 0.099ms

foreach wins on this case.

[michalsn]

Okay, now it looks good. Thanks.