# parameters An array of parameter names to extract. ``` var parameters: [String]? ``` ## Discussion Use a value of `nil` to include all query items. If you specify an array for `parameters`, the parser includes the query items in the result, in the specified order. For example, setting `parameters` to `["id", "external"]` parses URL `http://example.com/a/b/c?external&id=123&type=abc` into `http://example.com/a/b/c?id=123&external`. Note in this example that the query separates items with the `&` character, and query items don’t necessarily have a value (such as `external` in this example). --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)