Dependency Injection

Introduction

Dependency Injection or DI is when we provides the things we need into another object.

Originally in OO is was thought better to hide the internal objects and create them inside the object.

class Car {
   Engine engine
   Wheels wheels;

   Car() {
      engine = new Engine()
      wheels = new Wheels()
   }

   void drive() {
     // chug chug
   }

}