Hi,

I hope I understand the question.

First, you do put things together :) However, as your print statement is in the block that does the joining you don't see the result. Put an extra foreach at the end to print out the result.

Second, why that last if...? You iterate @tojoin over %item so that you'll end up only with:

A
B
C
AW
AX
AY
AZ
BW
BX
BY
BZ
CW
CX
CY
CZ

Is this what you want?

#!/usr/bin/perl

my %line = ('A' =>1,
            'B' =>1,
            'C' =>1);

my @tojoin = qw (W X Y Z);


foreach  my $line ( keys %line  )
{
#   print "$line\n";

   foreach my $tojoin ( @tojoin  )
   {
      my $nstr = $line.$tojoin;
      $line{$nstr} = 1;
   }           
#     last if ($line eq 'AYW');

}

foreach my $line ( keys %line ) {
    print "$line\n";
}
[download]

Of course, A, B and C stay in the original %item. You might need to delete them:

...
foreach  my $line ( keys %line  )
{
#   print "$line\n";
   delete $line{$line};

   foreach my $tojoin ( @tojoin  )
   {
      my $nstr = $line.$tojoin;
      $line{$nstr} = 1;
   }           
#     last if ($line eq 'AYW');

}
...
[download]