Type Hinting and Dependency Injection

Type hinting injected objects

Though type hinting is not necessary for dependency injection, it is preferred in situations when we want to check the dependency of the main class on types of objects. In our example, we expect any Driver class that uses the Car object to also have a sayYourName() method. To do that, let’s create a Driver interface and make both HumanDriver and RobotDriver classes implement the interface.