> For the complete documentation index, see [llms.txt](https://cours.davidannebicque.fr/symfony/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cours.davidannebicque.fr/symfony/version-4.1/services.md).

# Services et Injection de dépendances

## Fetching Services

Symfony comes packed with a lot of useful objects, called services. These are used for rendering templates, sending emails, querying the database and any other "work" you can think of.

If you need a service in a controller, type-hint an argument with its class (or interface) name. Symfony will automatically pass you the service you need:

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```php
use Psr\Log\LoggerInterface 

//...

/**
* @Route("/lucky/number/{max}")
*/
public function number($max, LoggerInterface $logger)
{
 $logger->info('We are logging!');
 // ...
}
```

* Awesome!