What Is Dependency Injection (DI)

Dependency Injection

Dependency Injection (DI) is a software design pattern that is commonly used in object-oriented programming to manage dependencies between different components of an application.

The idea behind DI is to decouple components by making them independent of each other's concrete implementations, and instead rely on abstractions or interfaces to define their dependencies. This allows for greater flexibility, modularity, and easier testing of the individual components.

In DI, the responsibility of creating and providing the necessary dependencies to a component is delegated to a separate object, typically referred to as an "injector" or a "container". This injector reads the configuration of the application and creates instances of the required dependencies, which are then passed to the component at runtime.

There are several ways to implement DI, such as constructor injection, setter injection, and interface injection. Regardless of the approach used, the main goal of DI is to enable loosely-coupled, modular and testable software components.