use strict;
use warnings;
use Benchmark;


sub fortest {
	my $number = 0;
	for(1 .. 100) {         
    	$number++ if $_ < 50; 
	}
}


sub greptest {
	my $number = 0;
	for(grep {$_ < 50} (1 .. 100)) {
    	$number++;
	}
}

my $count = 100000;

timethese( $count, {
	'for' => \&fortest,
	'grep' => \&greptest 
} );

__OUTPUT__

Benchmark: timing 100000 iterations of for, grep...
  for:  5 wallclock secs ( 4.85 usr +  0.02 sys =  4.87 CPU) @ 20546.54/s (n=100000)
  grep:  6 wallclock secs ( 5.16 usr +  0.00 sys =  5.16 CPU) @ 19387.36/s (n=100000)

##</code><code>##

use strict;
use warnings;
use Benchmark;

sub perlish_for {
	my $iterator = 0;
	my $array_ref = [1 .. 10000];
	for(@$array_ref) {
    	$iterator++;
	}
}

sub cish_for {
	my $iterator = 0;
	my $array_ref = [1 .. 10000];
	for(my $i=0; $_ = $array_ref->[$i] ;$i++) {
    	$iterator++;
	}
}


my $count = 1000;

timethese( $count, {
	'Perlish' => \&perlish_for,
	'C-ish' => \&cish_for 
} );

__OUTPUT__

Benchmark: timing 1000 iterations of C-ish, Perlish...
   C-ish:  9 wallclock secs ( 8.42 usr +  0.02 sys =  8.44 CPU) @ 118.46/s (n=1000)
   Perlish:  7 wallclock secs ( 6.67 usr +  0.06 sys =  6.73 CPU) @ 148.61/s (n=1000)