What is Dependency Injection?

Dependency Injection (DI) is a software design pattern. It allows us to develop loosely-coupled code. The intent of Dependency Injection is to make code maintainable. Dependency Injection helps to reduce the tight coupling among software components. DI is an implementation of the Inversion of control (IoC) principle.

Dependency Injection reduces the hard-coded dependencies among your classes by injecting those dependencies at run time instead of design time technically.

Constructor Injection is the most commonly used dependency pattern in Object Oriented Programming. The constructor injection normally has only one parameterized constructor, so in this constructor dependency there is no default constructor and we need to pass the specified value at the time of object creation.