> For the complete documentation index, see [llms.txt](https://www.learnrxjs.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.learnrxjs.io/learn-rxjs/operators/utility/finalize.md).

# finalize / finally

#### signature: `finalize(callback: () => void)`

## Call a function when observable completes or errors

### Examples

**Example 1: Execute callback function when the observable completes**

( [StackBlitz](https://stackblitz.com/edit/typescript-ohddud) )

```js
import { interval } from 'rxjs';
import { take, finalize } from 'rxjs/operators';

//emit value in sequence every 1 second
const source = interval(1000);
//output: 0,1,2,3,4,5....
const example = source.pipe(
  take(5), //take only the first 5 values
  finalize(() => console.log('Sequence complete')) // Execute when the observable completes
)
const subscribe = example.subscribe(val => console.log(val));
```

### Related Recipes

* [Battleship Game](/learn-rxjs/recipes/battleship-game.md)
* [Car Racing Game](/learn-rxjs/recipes/car-racing-game.md)
* [Click Ninja Game](/learn-rxjs/recipes/click-ninja-game.md)
* [HTTP Polling](/learn-rxjs/recipes/http-polling.md)
* [Mine Sweeper Game](/learn-rxjs/recipes/mine-sweeper-game.md)
* [Swipe To Refresh](/learn-rxjs/recipes/swipe-to-refresh.md)
* [Tetris Game](/learn-rxjs/recipes/tetris-game.md)

### Additional Resources

* [finalize](https://rxjs.dev/api/operators/finalize) 📰 - Official docs

***

> 📁 Source Code: <https://github.com/ReactiveX/rxjs/blob/master/packages/rxjs/src/internal/operators/finalize.ts>


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