Angular Interview Questions

Angular is a platform and framework for building single-page client applications using HTML and TypeScript. Developed and maintained by Google, it provides a robust set of tools and libraries that help developers create dynamic, high-performance web applications efficiently.

Key Features of Angular:

1. Component-Based Architecture:
   Angular applications are built using a component-based architecture. Components are the basic building blocks of an Angular application, encapsulating the HTML, CSS, and JavaScript that define a piece of the user interface.

2. TypeScript:
   Angular is written in TypeScript, a superset of JavaScript that offers static typing and other advanced features. TypeScript helps developers catch errors early through type checking and provides powerful tools like interfaces and decorators.

3. Dependency Injection:
   Angular uses a hierarchical dependency injection system, which makes it easy to manage and inject dependencies. This leads to better organization and more testable code.

4. Two-Way Data Binding:
   Angular supports two-way data binding, which allows automatic synchronization of data between the model and the view. This makes it easier to handle user input and dynamic updates in the user interface.

5. Directives:
   Directives are special markers in the DOM that extend the HTML capabilities. Angular provides built-in directives (like ngFor and ngIf) and allows developers to create custom directives to manipulate the DOM in a declarative manner.

6. Services and Dependency Injection:
   Services in Angular are used to share data and logic across different components. Combined with dependency injection, services promote code reusability and separation of concerns.

7. Routing:
   Angular’s powerful router enables navigation between different views or components. It supports lazy loading, which can improve the performance of the application by loading only the necessary parts of the app.

8. Reactive Programming with RxJS:
   Angular integrates with RxJS, a library for reactive programming using Observables, which makes handling asynchronous operations and events more manageable and efficient.

9. Modular Structure:
   Angular encourages a modular approach to development, where an application is divided into feature modules. This enhances code organization, maintainability, and scalability.

10. CLI (Command Line Interface):
    Angular CLI is a powerful tool that helps in automating various development tasks such as project setup, scaffolding, building, and testing. It speeds up the development process and ensures best practices are followed.

11. Testing:
    Angular has strong support for unit testing and end-to-end testing, with tools like Jasmine and Protractor integrated into the development workflow.

12. Ahead-of-Time (AOT) Compilation:
    Angular supports Ahead-of-Time compilation, which compiles the application during the build process, resulting in faster rendering and improved performance.

These features make Angular a comprehensive framework for building sophisticated and high-performing web applications, suitable for both small and large-scale projects.