Hello henzcoop,

You’re nearly there. But (1) eval returns the value of the last expression evaluated; but you don’t want the number of transliterations, you want the transliterated string, which is $message. (2) Within an eval, a variable such as $message will itself be interpolated. But you want to evaluate the expression $message =~ ..., so you need to escape the $ sigil to prevent interpolation of the $message variable into the string to be evaluated.

#! perl
use strict;
use warnings;

print "Please enter your message to be encrypted.\n";

my $message = <STDIN>;
chomp($message);

# generate randomized alphabet
my @chars = ("A".."Z", "a".."z");
my $string;
$string .= $chars[rand @chars] for 1..26;

# I want to drop the random alphabet in $string into the replace-with 
+slot of tr//
eval "\$message =~ tr/a-z/$string/;";

print "Here is your encrypted message: $message\n";
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Alternatively, you can add an /r modifier to the transliteration to get it to return the transliterated value:

my $code = eval "\$message =~ tr/a-z/$string/r;";

print "Here is your encrypted message: $code\n";
[download]

See the entry for tr/SEARCHLIST/REPLACEMENTLIST/cdsr under perlop#Quote-Like-Operators.

Hope that helps,