use strict;
use warnings; # Assuming you're using Perl 5.6.0 and higher

my %vars = (
    'A' => 'This is varA',
    'B' => 'This is varB',
    'C' => '',
);

my @vars = qw( A B C );

foreach my $varname ( @vars ) {
    print "$varname is $vars{ $varname }\n";
}