Angular Interview Practice 2025 – The Comprehensive All-in-One Guide to Excel in Your Interview!

The use of the @Injectable decorator in Angular is primarily associated with enabling dependency injection for services. When a class is marked with @Injectable, it signifies that the class may have dependencies that need to be injected into it when Angular creates an instance of the class, typically a service. This allows Angular's injector to know how to create instances of that class and manage its dependencies efficiently.

By facilitating dependency injection, the @Injectable decorator supports the inversion of control, allowing components and services to be loosely coupled. This promotes better organization of code, makes it easier to manage the application's state, and allows for easier unit testing since dependencies can be mocked or replaced.

For example, if a service requires another service as a dependency, using @Injectable ensures that Angular can correctly provide that necessary dependency when the first service is instantiated. This functionality encourages developers to create modular, maintainable, and reusable pieces of code.

In contrast, concepts such as data binding to components, creating reusable code with classes, and event handling are important but are not directly tied to the @Injectable decorator's primary purpose regarding dependency injection.