hash keys come in any order at all (not like an array where there is a fixed order). To print in alphabetic order you need to sort the keys.

#!/usr/bin/perl
use strict;
use warnings;

my %hash2=(
             c => "cat",
             a => "apple",
             b => "boy",
          );

my @keys= sort keys %hash2; 
foreach my $s (@keys)
{
    print "$hash2{$s} ";
}
__END__
prints: apple boy cat
[download]