But my code above doesn't print anything.

It's worse than that - your code doesn't compile:

$ perl -cw 11100018.pl 
Can't locate stricts.pm in @INC (you may need to install the stricts m
+odule) (@INC contains: /usr/local/lib64/perl5 /usr/local/share/perl5 
+/usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/
+perl5 /usr/share/perl5 .) at 11100018.pl line 3.
BEGIN failed--compilation aborted at 11100018.pl line 3.
[download]

Here's something which is what I think you might want instead.

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

my @array = qw/b d a c/;

my %hash = (
    a  => 200,
    b  => 100,
    c  => 30,
    d  => 40
);

for my $key (sort @array) {
    if ($hash{$key}) {
        print "array element: $key = $hash{$key} inside \%hash\n";
    }
}
[download]