WooCommerce - Change default checkout fields placeholders

<?php
  // Change default checkout fields placeholders
  // code goes in functions.php for your child theme
  add_filter('woocommerce_checkout_fields', 'custom_override_placeholders')
  function custom_override_placeholders($address_fields) {
    $address_fields['address_1']['placeholder'] = 'House';
    $address_fields['address_2']['placeholder'] = 'Street';
    $address_fields['county']['placeholder'] = 'County';
    $address_fields['postcode']['placeholder'] = 'Postcode';
    return $address_fields;
  }