Actual software projects will usually combine multiple components that will have to be used together. Most of the time, these components will depend on others, which in turn depend on other components, and so on. This makes creating objects in an application hard because we also need to create the objects they depend on and so on. This is where dependency injection comes in handy.
The cake design pattern
Dependency injection
So, what exactly is dependency injection? It turns out to be something really simple—every single class that has an object as a parameter in their constructor is actually an example of a dependency injection. The reason is that the dependency is injected into the class rather than instantiated inside...