#!/usr/bin/perl -w

use strict;

use vars qw(@array);
@array = qw(a b c d e f g h i j k l m n o p q r s t u v w x y z);

use vars qw($test);
if ($ARGV[0] eq "1")
{
  $test = sub {
    print "Found!\n" if index("@array", $_[0]) > 1;
  }
}
elsif ($ARGV[0] eq "2")
{
  $test = sub {
    print "Found!\n" if grep { $_ eq $_[0] } @array;
  }
}
else
{
  die "Usage: $0 1|2\n";
}

for(my $i=0;$i<1_000_000;$i++)
{
  &$test(chr(ord('m') + ($i % 26)));
}
[download]

$ time perl ~/tmp/t5 1 |wc -l
 538468

real	0m13.711s
user	0m12.000s
sys	0m0.020s
$ time perl ~/tmp/t5 2 |wc -l
 538468

real	0m19.380s
user	0m19.330s
sys	0m0.050s