#!/usr/bin/perl

use strict;
use warnings;

my $config = {
  count => {
    x => 9,
    y => 14,
  },
  other => {
    a => 1,
    b => 2,
  }
};

my $some_variable = 'x';

die "bad count" unless exists $config->{count}{$some_variable};

for my $i (0 .. $config->{count}{$some_variable}) {
   #do some stuff;
}