The Camel book has the following for-loop for enumerating all the variables in a package:

package Test;
$testing = 'TEST';
@test_array = (qw/OneTest TwoTest/);
%test_hash = ('testkey' => 'testvalue');

foreach $symname (sort keys %Test::) {
    local *sym = $Test::{$symname};
    print "\$$symname is defined\n" if defined $sym;
    print "\@$symname is nonnull\n" if         @sym;
    print "\%$symname is nonnull\n" if         %sym;
}
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package Test;
$testing = 'TEST';
@test_array = (qw/OneTest TwoTest/);
%test_hash = ('testkey' => 'testvalue');

foreach my $symname (sort keys %Test::) {
    local *sym = $Test::{$symname};
    if (defined $sym) {$sym = undef; print "\$$symname is cleared\n" }
+;
    if         (@sym) {@sym = undef; print "\@$symname is cleared\n" }
+;
    if         (%sym) {%sym = undef; print "\%$symname is cleared\n" }
+;
}
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It is not a full solution: it will not work under strict (note: lexical variables are not part of any package) and will be dangerous if used in the main package as it will undef also all the special variables

$variable{'a'} = 1;
$variable{'b'} = $variable{'a'} + 1;

foreach my $k (keys %variable) {$variable{$k} = $reset_value;}
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Nice try! As a matter of fact, all variables are already in a hash: %main:: for the main package.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

Not really, not perfectly. What are you trying to do.

Well witin my application, i have a reset button. I would like to undef all my var's that are currently defined. Instead of going though each var and undef them, i though it might be eaiser if there was a way to build a list into an array and just irrate though the array and undef them.

Surely you don't want to reset everything, as that would also reset things like @INC, making your program a little brain-dead. I mean, that's one of the reasons that perldoc -f reset includes the paragraph:

            Resetting "A-Z" is not recommended because you'll wipe out
+ your
            @ARGV and @INC arrays and your %ENV hash. Resets only pack
+age
            variables--lexical variables are unaffected, but they clea
+n
            themselves up on scope exit anyway, so you'll probably wan
+t to
            use them instead. See "my".
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The proper way to go about this is to use proper objects in your program, so that you can have a top level object that is associated with a particular session, and everything else hangs off of that. Then, to reset the session, just generate a new session object.

-- Randal L. Schwartz, Perl hacker

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

If you want to start with a fresh slate, it's easy. Assuming you haven't changed the current directory or clobbered @ARGV,

exec $^X, $0, @ARGV
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Note: That won't pass to the new interpreter options that were passed to the first (like -p), but I bet that's not an issue for you.

Update: Added note.

Why not just restart application?

This comes close:

use strict;
use Data::Dumper;

my @array = ('A', 'b', undef, 0, 1, '', 'THE END');
$array[10] = 'The Real End';

my @defined_array = grep {defined} @array;

print Dumper(\@array, \@defined_array);
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$VAR1 = [
          'A',
          'b',
          undef,
          0,
          1,
          '',
          'THE END',
          undef,
          undef,
          undef,
          'The Real End'
        ];
$VAR2 = [
          'A',
          'b',
          0,
          1,
          '',
          'THE END',
          'The Real End'
        ];
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