my @a1 = qw(My name is Andrew);
my @a2 = qw(My dog named  Andrew);

##</code><code>##

foreach my $a1 (@a1){
  $i++;
  #print $a1 . "\n"; 
}

##</code><code>##

First:for($a = 0; $a <= $i; $a++){
    Second:for($s = 0; $s <= $i; $s++){
        my $d = 0;
        print $a.$t;
        print $s.$n;
        if($a!=$s){
        print "Yes.->".$a.$s.$n; last}
        print "system command \$a $a, then for \$s $s".$n;
        $d++;
    }
}

##</code><code>##

use strict;
use warnings;

my @a1 = qw(My name is     Andrew);
my @a2 = qw(My  dog named  Andrew);

my $i = 0;
while ($a1[$i] and $a2[$i]) { # make sure something is in both arrays
    if ($a1[$i] ne $a2[$i]) {
        print "system command \$a1 $a1[$i], then for \$a2 $a2[$i]\n";
    }
    else {
        print "# \$a1 $a1[$i], and \$a2 $a2[$i] are the same\n";
    }
    $i++;
}