#!/usr/bin/perl -wT
use strict;

my @arr  = qw(a b c d e);     # make a non-empty array
my @arr2 = qw();              # make an empty array

my $val  = isempty(\@arr);    # check if arr isempty
my $val2 = isempty(\@arr2);   # check if arr2 isempty

print "\@arr ",  $val  ? 'is' : 'is not', " empty.\n";
print "\@arr2 ", $val2 ? 'is' : 'is not', " empty.\n";

sub isempty {
   my $aref = shift;          # get array ref as param
   return !@$aref;            # check array for emptiness
}

=output
@arr is not empty.
@arr2 is empty.