title: WooCommerce checkout postcode field order
body: <p>I'm trying to modify the checkout page. Using a plugin I was able to replace the two default address lines with a street, house number and 'extra' field (they're all on one line). Below that, you find the postcode and the city field. <br>However, I want to generate the street and city when the user enters their postcode and housenumber, so I want to switch the fields. <br>It's like this:</p>
  
  <blockquote>
    <p>Street - Housenumber - Extra<Br />
    Postcode - City</p>
  </blockquote>
  
  <p>I want it to be:</p>
  
  <blockquote>
    <p>Postcode - Housnumber - Extra <Br />
    Street - City</p>
  </blockquote>
  
  <p>I'm using the regular hook:</p>
  
  <pre><code>add_filter("woocommerce_checkout_fields", "order_fields");
  
  function order_fields($fields) {
  
      $order = array(
          "billing_first_name", 
          "billing_last_name", 
          "billing_company", 
          "billing_street",                       
          "billing_house_number",
          "billing_house_number_extra",
          "billing_postcode",
          "billing_city",
          "billing_country", 
          "billing_email", 
          "billing_phone"
  
      );
      foreach($order as $field)
      {
          $ordered_fields[$field] = $fields["billing"][$field];
      }
  
      $fields["billing"] = $ordered_fields;
      return $fields;
  
  }
  </code></pre>
  
  <p>However... trying to move the postcode field is unsuccesful. If I move the postcode and city field together I'm able to move them, but just trying to move the postcode field seperate shows strange behaviour <em>(For instance: switching out the street and postcode field)</em>. </p>
  
  <p>What am I missing?</p>