#!/usr/bin/env perl

use strict;
use warnings;

my @array_H = (
  'ABCD',
  1234,
  '1234',
  ' 1234'
);

foreach my $ele ( @array_H ) {
  if( $ele !~  /^[0-9]+$/ ) {
    block( $ele );
  }
}

sub block {
  my $ele = shift;
  print "Woot -- $ele --\n";
}

##</code><code>##

Woot -- ABCD --
Woot --  1234 --