1. What is Angular?

  • Angular is a TypeScript-based open-source framework for building dynamic, single-page web applications (SPAs).

2. What are the key features of Angular?

  • Key features of Angular include two-way data binding, dependency injection, components, services, and a powerful template system.

3. What is TypeScript, and why is it used in Angular?

  • TypeScript is a statically typed superset of JavaScript. It is used in Angular for its strong typing and improved tooling support.

4. Explain Angular's two-way data binding.

  • Two-way data binding in Angular allows automatic synchronization of data between the view and the model. Changes in the view update the model, and vice versa.

5. What is a component in Angular?

  • A component in Angular is a self-contained, reusable building block that encapsulates HTML templates, styles, and TypeScript code.

6. How do you create a new Angular project?

  • You can create a new Angular project using the Angular CLI (Command Line Interface) with the ng new command.

7. What is dependency injection in Angular?

  • Dependency injection is a design pattern used in Angular to provide and manage dependencies for components and services.

8. How do you create a custom component in Angular?

  • You can create a custom component using the Angular CLI with the ng generate component command.

9. What is a service in Angular, and why is it used?

  • A service in Angular is a reusable code unit used to encapsulate and provide specific functionality or data across components.

10. Explain the difference between Angular modules and NgModule. - Angular modules are used to organize and group related components, directives, and services. NgModule is a decorator used to define Angular modules.

11. What is a directive in Angular? - A directive is a custom HTML attribute or element that provides additional behavior to the DOM.

12. What is a template in Angular? - A template in Angular is an HTML view that defines the structure of a component.

13. How do you implement routing in Angular? - You can implement routing in Angular using the RouterModule and RouterOutlet to navigate between different views.

14. What is the purpose of Angular's HttpClient module? - Angular's HttpClient module is used for making HTTP requests to fetch data from a server or interact with RESTful APIs.

15. What is an Angular service worker, and what is its role? - An Angular service worker is used for enabling Progressive Web App (PWA) features such as offline caching and push notifications.

16. How do you handle forms in Angular? - Angular provides two types of forms: template-driven forms and reactive forms (model-driven forms), both of which allow you to handle form data.

17. Explain the Angular ngFor directive. - ngFor is used for looping through elements in an array and rendering them in the template.

18. What is the purpose of Angular CLI, and how do you use it? - Angular CLI is a command-line tool that simplifies various development tasks, such as project setup, component generation, and deployment.

19. How can you share data between components in Angular? - Data can be shared between components using Input and Output properties, services, or state management libraries like NgRx.

20. What are Angular pipes, and how are they used? - Angular pipes are used for transforming data in the template, such as formatting dates or numbers.

21. Explain Angular's AOT (Ahead-of-Time) compilation. - AOT compilation is a build process that converts Angular templates and components into highly optimized JavaScript code for faster application loading.

22. How do you perform unit testing in Angular? - Angular provides built-in support for unit testing using testing frameworks like Jasmine and tools like Karma.

23. What is Angular CLI schematics? - Angular CLI schematics are code generators that allow you to create custom blueprints for generating components, modules, and other Angular artifacts.

24. What is lazy loading in Angular, and why is it important? - Lazy loading is a technique in Angular where modules and their associated components are loaded only when needed, improving application performance.

25. Explain Angular's HTTP Interceptors. - HTTP Interceptors in Angular allow you to intercept and modify HTTP requests and responses globally.

26. What is the purpose of Angular's ViewChild and ViewChildren decorators? - @ViewChild and @ViewChildren decorators are used to access child components, elements, or directives from a parent component's template.

27. How can you optimize an Angular application's performance? - Performance optimization in Angular can be achieved through techniques such as lazy loading, AOT compilation, tree-shaking, and code splitting.

28. What are Angular services, and how do you create one? - Angular services are used to encapsulate reusable functionality or data. You can create a service using the Angular CLI or manually.

29. Explain Angular's ngIf directive. - ngIf is a structural directive used to conditionally render or remove elements from the DOM based on a Boolean expression.

30. What is change detection in Angular? - Change detection is the process by which Angular determines when to update the view based on changes in the application's state.

31. How do you implement authentication in an Angular application? - Authentication can be implemented using services and libraries like AngularFire or JSON Web Tokens (JWT) in conjunction with an authentication API.

32. What is Angular Universal, and why is it used? - Angular Universal is a technology for server-side rendering (SSR) of Angular applications to improve initial page load times and SEO.

33. How do you prevent Cross-Site Scripting (XSS) attacks in Angular? - Angular automatically sanitizes user inputs and uses a security model to prevent XSS attacks.

34. Explain Angular's ElementRef and Renderer2. - ElementRef is used to access the DOM element of a component. Renderer2 is used to manipulate the DOM safely and efficiently.

35. What is a resolver in Angular, and how is it used? - A resolver is used to fetch data before a route is activated, ensuring that data is available when the component is rendered.

36. What are Angular forms validators, and how do you use them? - Angular provides built-in and custom validators for form validation. Validators can be added to form controls to enforce data validation rules.

37. How do you handle internationalization (i18n) in Angular? - Angular provides tools for internationalization, including translation files and the Angular i18n module.

38. Explain Angular's ElementRef and Renderer2. - ElementRef allows you to access the DOM element of a component, while Renderer2 is used to safely manipulate the DOM.

39. What is the purpose of Angular's trackBy function in ngFor? - trackBy is used with ngFor to improve rendering performance by providing a unique identifier for each item in the iterable.

40. How do you use Angular's ngStyle and ngClass directives? - ngStyle is used to dynamically apply CSS styles, and ngClass is used to add or remove CSS classes based on conditions.

41. What is Angular's HttpClient Interceptor, and why is it useful? - An HttpClient Interceptor in Angular allows you to intercept HTTP requests and responses globally and apply common logic or headers.

42. What is Angular Material, and how does it relate to Angular? - Angular Material is a UI component library for Angular that provides pre-designed and customizable UI components to simplify the creation of modern web applications.

43. How do you implement lazy loading in Angular for modules and routes? - Lazy loading in Angular can be implemented by using the loadChildren property in the route configuration and creating separate feature modules.

44. What is the purpose of Angular's ngZone? - NgZone in Angular helps manage the change detection mechanism and improves performance by running tasks outside the Angular zone.

45. How do you handle route guards in Angular? - Route guards are used to control navigation and protect routes based on conditions. You can implement them using CanActivate, CanDeactivate, and other guard interfaces.

46. Explain the role of Angular's TestBed in unit testing. - TestBed is used in Angular unit testing to configure a testing module and create instances of components for testing.

47. What is the purpose of Angular's async pipe? - The async pipe is used in templates to automatically subscribe to and unsubscribe from observables, making it easier to work with asynchronous data.

48. What is Angular's ngZone, and why is it important? - NgZone is an Angular service that helps manage change detection and execution outside the Angular zone, improving performance.

49. What are the key differences between AngularJS (Angular 1.x) and Angular (Angular 2+)? - Some key differences include the use of TypeScript, a component-based architecture, improved performance, and a completely rewritten framework in Angular.

50. How can you deploy an Angular application to a production server? - You can build and deploy an Angular application to a production server using the ng build command and hosting it on a web server or cloud platform.