Performace calculation

anniyan has asked for the wisdom of the Perl Monks concerning the following question:

Monks, now i am doing a small tool, in that i need to split the string into two, i want to know among the two methods which is the best method, else is there any other best way to do this?

I come up with this question because in our community often there is a discussion regarding the performance. Often i use to see the nodes saying dont call the regex engine unnecessarily?

If there is some conclusion out of this i will follow that in the future.

method1:
$item = 'path/path1==new';
my ($epath, $relt) =  split /==/, $item;
[download]

method2:
$item = 'path/path1==new';
my ($epath, $relt) =  $item =~ /([^=]*)==(.*)/;
[download]

Please apologise if it is silly.

Regards,
Anniyan
(CREATED in HELL by DEVIL to s|EVILS|GOODS|g in WORLD)

Comment on Performace calculation Select or Download Code

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Re: Performace calculation by Perl Mouse (Chaplain) on Nov 23, 2005 at 12:21 UTC
Unless you are doing this thousands of times, it will hardly matter which one is faster. If you must know, you can always use the Benchmark module, and run a simple test: `#!/usr/bin/perl use strict; use warnings; use Benchmark 'cmpthese'; our $item = '"path/path1==new'; cmpthese(-1, { method1 => 'my ($epath, $relt) = split /==/, $item', method2 => 'my ($epath, $relt) = $item =~ /([^=])==(.)/', }); __END__ Rate method2 method1 method2 334042/s -- -38% method1 535924/s 60% --` [download] Method 1 will about 1.1 microseconds faster (at least, on my box). So, if I have a million of them, method1 will gain 1 second over method2. That's hardly worth the trouble. I'd pick method1 because, IMO, it's more clear to see what it does. Oh, and both methods use a regular expression anyway. `Perl --((8:>*`	[reply] [d/l]
Re: Performace calculation by murugu (Curate) on Nov 23, 2005 at 12:37 UTC
Hi anniyan, In both the cases you are using regexp. Method1 seems faster than method2. To benchmark the code, go for Benchmark module Here is the comparison.... `use strict; use warnings; use Benchmark qw(cmpthese); cmpthese(-1, {method1=>sub {my $item = 'path/path1==new';my ($epath, $relt) = spli +t /==/, $item;},method2=>sub {my $item = 'path/path1==new';my ($epath +, $relt) = $item =~ /([^=])==(.)/;} } ); Rate method2 method1 method2 200037/s -- -37% method1 315836/s 58% --` [download] Regards, Murugesan Kandasamy use perl for(;;);	[reply] [d/l]