What are the different ways of dependency injection in Laravel?

In Laravel, dependency injection can be achieved using the following methods:

1. Constructor injection involves declaring dependencies in a class’s constructor and passing those dependencies as parameters to the constructor.

Sample code:

class UserController
{
    protected $userService;

    public function __construct(UserService $userService)
    {
        $this->userService = $userService;
    }

    public function index()
    {
        // 使用 $this->userService 调用相关方法
    }
}

1. Method injection: declaring dependencies within a method and passing them as parameters to the method.

Example code:

class UserController
{
    protected $userService;

    public function index(UserService $userService)
    {
        $this->userService = $userService;

        // 使用 $this->userService 调用相关方法
    }
}

1. Service container: Resolve dependencies using Laravel’s service container.

Example code:

class UserController
{
    protected $userService;

    public function index()
    {
        $this->userService = app(UserService::class);

        // 使用 $this->userService 调用相关方法
    }
}

These are several common ways of dependency injection, you can choose the suitable method according to the specific situation.