Question

Can you briefly explain: What mainly differs Dependency Injection from Factory Design pattern?

Additionally: Is it possible to demonstrate the difference very simply by a code example?

Thanks

Answer 1

With Factory (or any other Creation pattern), the caller has to know how to get the object and has to “explicitly” ask for it before consuming it.

Car car = CarFactory.getCarByModel(LUXURY);

Whereas when using DI, the responsibility to pass the desired object is delegated to some external (container mostly) entity which knows how to create the object (by reading the config already defined) and make it available to the caller silently.

Car car = getCar();
void setCar(Car car){..} // container sets the car fromoutside