Laravel容器和装订

Question

Laravel 5.6 Documentation says:

There is no need to bind classes into the container if they do not depend on any interfaces. The container does not need to be instructed on how to build these objects, since it can automatically resolve these objects using reflection.

I don't understand it.

Does it mean that I don't have to use any bindigs inside provider's register method if I don't use interfaces?

Then, how can I use dependency injection if I don't use bindigs?

P.S.: in my understending:

"interface" - is this

"bindings" - is bind() and singelton() inside register

Answer 1

If you have :

class Something {

}

You can do app()->make(Something::class) without needing to bind it before hand. The container knows that it can just call the default constructor.

The same goes for

class SomethingElse {
       public function __construct(Something $s) { }
}   

In this case the constructor will also go through the dependency injection. This is all handled automatically by the container.

However this obviously cannot work for interfaces since interfaces can't be constructed.

Also if you need something to be bound as a singleton you need to bind it explicitly using app()->singleton(...)