A[] cast = (A[]) result;
    return cast;
  }

  @Override
  public boolean equals(@Nullable Object obj) {
    if (obj instanceof Parameter) {
      Parameter that = (Parameter) obj;
      return position == that.position && declaration.equals(that.declaration);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return position;
  }

# Request Parameters

Here's the reference information for the request parameters.

These are the special functions that you can put in *path operation function* parameters or dependency functions with `Annotated` to get data from the request.

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python

    * Jeżeli nie jest, odbiorca zobaczy przydatną, przejrzystą wiadomość z błędem.
* Sprawdzi czy w ścieżce jest opcjonalny parametr zapytania `q` (np. `http://127.0.0.1:8000/items/foo?q=somequery`) dla żądania `GET`.
    * Jako że parametr `q` jest zadeklarowany jako `= None`, jest on opcjonalny.
    * Gdyby tego `None` nie było, parametr ten byłby wymagany (tak jak treść żądania w żądaniu `PUT`).

## `BackgroundTasks` verwenden

Importieren Sie zunächst `BackgroundTasks` und definieren Sie einen Parameter in Ihrer *Pfadoperation-Funktion* mit der Typdeklaration `BackgroundTasks`:

{* ../../docs_src/background_tasks/tutorial001.py hl[1,13] *}

**FastAPI** erstellt für Sie das Objekt vom Typ `BackgroundTasks` und übergibt es als diesen Parameter.

## Eine Taskfunktion erstellen

* Anche la documentazione alternativa dell'API mostrerà il nuovo parametro della query e il _body_:

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Riepilogo

Ricapitolando, è sufficiente dichiarare **una sola volta** i tipi dei parametri, del body, ecc. come parametri di funzioni.

Questo con le annotazioni per i tipi standard di Python.

# Body - Multiple Parameters { #body-multiple-parameters }

Now that we have seen how to use `Path` and `Query`, let's see more advanced uses of request body declarations.

## Mix `Path`, `Query` and body parameters { #mix-path-query-and-body-parameters }

First, of course, you can mix `Path`, `Query` and request body parameter declarations freely and **FastAPI** will know what to do.

///

### Declarar un *path parameter*

Luego crea un *path parameter* con una anotación de tipo usando la clase enum que creaste (`ModelName`):

{* ../../docs_src/path_params/tutorial005.py hl[16] *}

### Revisa la documentación

Como los valores disponibles para el *path parameter* están predefinidos, la documentación interactiva puede mostrarlos de manera ordenada:

Both of those versions mean the same thing, `q` is a parameter that can be a `str` or `None`, and by default, it is `None`.

Now let's jump to the fun stuff. 🎉

## Add `Query` to `Annotated` in the `q` parameter { #add-query-to-annotated-in-the-q-parameter }

Now that we have this `Annotated` where we can put more information (in this case some additional validation), add `Query` inside of `Annotated`, and set the parameter `max_length` to `50`:

In this case, the function parameter `q` will be optional, and will be `None` by default.

/// check

Also notice that **FastAPI** is smart enough to notice that the path parameter `item_id` is a path parameter and `q` is not, so, it's a query parameter.

///

## Query parameter type conversion { #query-parameter-type-conversion }

You can also declare `bool` types, and they will be converted:

If you want to:

* declare the `q` query parameter without a `Query` nor any default value
* declare the path parameter `item_id` using `Path`
* have them in a different order
* not use `Annotated`

...Python has a little special syntax for that.

Pass `*`, as the first parameter of the function.