Engineer Sushil Kumar Sushil Kumar Profile
1. What is Angular?
Answer: Angular is a platform and framework for building single-page client applications using HTML and TypeScript. It is developed and maintained by Google.
2. What is TypeScript?
Answer: TypeScript is a superset of JavaScript that adds static typing to the language. Angular applications are written in TypeScript.
3. What are Angular components?
Answer: Components are the fundamental building blocks of Angular applications. They control a patch of screen called a view.
4. What is a module in Angular?
Answer: A module is a container for a group of related components, services, directives, and pipes. An Angular application is defined by a set of NgModules.
5. What is a directive in Angular?
Answer: Directives are classes that add additional behavior to elements in your Angular applications. There are three types: components, attribute directives, and structural directives.
6. What are services in Angular?
Answer: Services are singleton objects that are used to organize and share code across the application. They can be injected into components and other services.
7. What is Dependency Injection in Angular?
Answer: Dependency Injection (DI) is a design pattern in which a class requests dependencies from external sources rather than creating them.
8. What is Angular CLI?
Answer: Angular CLI (Command Line Interface) is a tool to initialize, develop, scaffold, and maintain Angular applications.
9. What is a template in Angular?
Answer: A template in Angular is a piece of HTML that tells Angular how to render the component.
10. What is data binding in Angular?
Answer: Data binding is a mechanism to synchronize data between the model and the view. Angular supports one-way, two-way, and event binding.
11. What is Angular routing?
Answer: Angular routing is a feature that enables navigation from one view to the next as users perform application tasks.
12. What are Angular Pipes?
Answer: Pipes are simple functions designed to accept an input value, process it, and return a transformed value.
13. What is the difference between a component and a directive?
Answer: A component is a directive with a template. Components are a special type of directive in Angular.
14. What is the purpose of NgModule?
Answer: NgModule is a decorator function that takes a single metadata object whose properties describe the module.
15. How does Angular handle events?
Answer: Angular provides event binding to handle events. You can bind to DOM events like click, change, or keyup using parentheses.
16. What are lifecycle hooks in Angular?
Answer: Lifecycle hooks are methods that Angular calls at specific stages of a component’s lifecycle, such as ngOnInit, ngOnChanges, ngOnDestroy, etc.
17. What is Angular Universal?
Answer: Angular Universal is a technology that allows you to run Angular applications on the server. This process is called server-side rendering (SSR).
18. What is AOT compilation?
Answer: AOT (Ahead-of-Time) compilation is the process of compiling Angular HTML and TypeScript code into JavaScript code during the build process, before the browser downloads and runs the code.
19. What is lazy loading in Angular?
Answer: Lazy loading is a technique in Angular to load NgModules on demand rather than all at once.
20. What is Angular Ivy?
Answer: Angular Ivy is the new rendering engine for Angular, designed to make applications faster and smaller.
21. How do you create a service in Angular?
Answer: You can create a service in Angular using the Angular CLI with the command ng generate service service-name.
22. What is Reactive Forms in Angular?
Answer: Reactive Forms provide a model-driven approach to handling form inputs whose values change over time.
23. What is the difference between Reactive Forms and Template-driven Forms?
Answer: Template-driven forms are asynchronous and easy to use, while Reactive Forms are synchronous and provide more powerful and flexible APIs.
24. How do you handle errors in Angular?
Answer: Errors can be handled in Angular using try-catch blocks, Angular’s ErrorHandler class, and observables’ catchError operator.
25. What is the purpose of the HttpClient module in Angular?
Answer: The HttpClient module is used to perform HTTP requests, allowing you to communicate with backend services over HTTP.
26. How do you perform unit testing in Angular?
Answer: Unit testing in Angular can be performed using Jasmine and Karma, which are included in the Angular CLI setup.
27. What is Angular Material?
Answer: Angular Material is a UI component library for Angular developers, based on Google’s Material Design principles.
28. What is NgRx?
Answer: NgRx is a set of reactive extensions for Angular, inspired by Redux, that manage application state in a predictable manner.
29. What is the purpose of the ng-template directive?
Answer: The ng-template directive is used to define template content that can be reused and conditionally rendered.
30. How do you optimize an Angular application for performance?
Answer: Performance can be optimized by lazy loading, using AOT compilation, caching, using OnPush change detection strategy, and minimizing bundle size.
31. What is the difference between ActivatedRoute and Router?
Answer: ActivatedRoute provides access to information about a route associated with a component that is loaded in an outlet, while Router is a service that provides navigation among views and URL manipulation capabilities.
32. What are resolvers in Angular?
Answer: Resolvers are used to pre-fetch data before navigating to a route.
33. What is the Angular Animation module?
Answer: The Angular Animation module allows you to create advanced animation effects within your Angular applications.
34. What is the purpose of the async pipe?
Answer: The async pipe subscribes to an Observable or Promise and returns the latest value it has emitted. It also marks the component to be checked for changes.
35. How do you create a custom directive in Angular?
Answer: A custom directive can be created using the @Directive decorator, and you define its behavior in the directive class.
36. What is the role of the BrowserModule in Angular?
Answer: The BrowserModule is required for any web-based Angular application and contains services and directives for rendering and bootstrapping the application.
37. How do you pass data between components in Angular?
Answer: Data can be passed between components using @Input() and @Output() decorators, services, and the shared state in NgRx.
38. What is the purpose of the Renderer2 class in Angular?
Answer: The Renderer2 class is used to manipulate DOM elements in a way that is platform-agnostic, helping with cross-browser compatibility.
39. What is Angular’s change detection strategy?
Answer: Angular’s change detection strategy determines how the framework checks for updates to the component’s data. The default strategy is CheckAlways, and the alternative is OnPush.
40. How do you implement route guards in Angular?
Answer: Route guards are implemented by creating services that implement the CanActivate, CanActivateChild, CanLoad, CanDeactivate, or Resolve interfaces.
41. What is a resolver in Angular routing?
Answer: A resolver is used to pre-fetch data before activating a route, ensuring the data is available as soon as the route is activated.
42. How do you share data between components without using parent-child relationship?
Answer: Data can be shared using services, NgRx, or local storage.
43. What are Angular templates?
Answer: Templates are HTML that render the component. They can include Angular directives, bindings, and expressions.
44. What is Angular’s module injector?
Answer: The module injector is a dependency injection container that is responsible for creating services and injecting them into components.
45. How do you define routes in Angular?
Answer: Routes are defined using the RouterModule and its forRoot() or forChild() methods.
46. What is a router outlet in Angular?
Answer: A router outlet is a directive that acts as a placeholder for the routed component view.
47. How do you handle HTTP errors in Angular?
Answer: HTTP errors can be handled using the catchError operator from RxJS in the HttpClient call.
48. What is the difference between an Observable and a Promise?
Answer: Observables are lazy and can emit multiple values over time, whereas Promises are eager and can only emit a single value once.
49. What is the use of the async pipe in Angular?
Answer: The async pipe automatically subscribes and unsubscribes from Observables or Promises, keeping the template clean and reducing boilerplate code.
50. How do you create a custom pipe in Angular?
Answer: A custom pipe can be created using the @Pipe decorator and implementing the PipeTransform interface.
51. How do you create a new Angular project?
Answer: Use Angular CLI to create a new project by running the command ng new project-name.
52. How do you generate a new component using Angular CLI?
Answer: Use the command ng generate component component-name or ng g c component-name.
53. How do you add Angular Material to your project?
Answer: Use the command ng add @angular/material.
54. How do you implement a service in Angular?
Answer: Create a service using the CLI ng generate service service-name and then inject it into your components or other services.
55. How do you fetch data from an API in Angular?
Answer: Use the HttpClient service to make HTTP requests. Inject HttpClient into your service and use methods like get(), post(), etc.
56. How do you handle HTTP errors in Angular?
Answer: Use the catchError operator from RxJS to handle errors in HTTP calls.
57. How do you implement routing in Angular?
Answer: Define routes in the AppRoutingModule and use the RouterModule.forRoot(routes) method to configure the router.
58. How do you pass data to a child component?
Answer: Use the @Input() decorator in the child component to receive data from the parent component.
59. How do you emit events from a child component to a parent component?
Answer: Use the @Output() decorator along with an EventEmitter to emit events to the parent component.
60. How do you create a form using Reactive Forms?
Answer: Import ReactiveFormsModule, create a FormGroup and FormControl in the component, and bind the form controls to the template using formGroup and formControlName directives.
61. How do you validate form inputs in Angular?
Answer: Use Angular validators such as Validators.required, Validators.minLength, etc., and apply them to form controls in Reactive Forms or template-driven forms.
62. How do you implement lazy loading in Angular?
Answer: Configure lazy loading by using the loadChildren property in your route definitions and setting it to the path of the module you want to load lazily.
63. How do you optimize an Angular application?
Answer: Use lazy loading, AOT compilation, tree shaking, minification, and optimization tools like Angular CLI’s ng build --prod command.
64. How do you create a custom directive?
Answer: Use the Angular CLI command ng generate directive directive-name, and implement your custom logic in the directive class.
65. How do you create a custom pipe?
Answer: Use the Angular CLI command ng generate pipe pipe-name and implement the PipeTransform interface in your pipe class.
66. How do you implement a guard to protect routes?
Answer: Create a guard using the CLI ng generate guard guard-name and implement the CanActivate interface to control access to routes.
67. How do you perform unit testing of an Angular component?
Answer: Write test cases using Jasmine and Karma. Use TestBed to configure the testing module and ComponentFixture to access the component instance.
68. How do you inject a service into a component?
Answer: Use the constructor of the component to inject the service by specifying it as a parameter.
69. How do you create and use a shared module?
Answer: Create a shared module using ng generate module shared, declare and export common components, directives, and pipes, and import this module into other modules.
70. How do you handle route parameters?
Answer: Use the ActivatedRoute service to access route parameters using the paramMap or snapshot property.
71. How do you implement Angular animations?
Answer: Import BrowserAnimationsModule, define animations using Angular’s trigger, state, style, transition, and animate functions, and bind animations to HTML elements using [@animationName].
72. How do you manage state in Angular using NgRx?
Answer: Install NgRx, create actions, reducers, selectors, and effects, and configure the store module in your application module.
73. How do you unsubscribe from observables in Angular?
Answer: Use the unsubscribe() method or the takeUntil operator from RxJS to manage subscriptions and prevent memory leaks.
74. How do you use the Angular async pipe?
Answer: Bind the async pipe to an observable in the template to automatically subscribe and unsubscribe from the observable.
75. How do you prefetch data for a route using resolvers?
Answer: Create a resolver service that implements the Resolve interface, fetch the required data, and configure the resolver in the route definition.
76. How do you configure global error handling in Angular?
Answer: Implement a global error handler by creating a service that implements the ErrorHandler interface and provide it in the providers an array of your modules.
77. How do you handle child routes?
Answer: Define child routes using the children property in your route configuration.
78. How do you set up Angular Environment configurations?
Answer: Use the src/environments folder to define different environment files like environment.ts and environment.prod.ts, and configure them in angular.json.
79. How do you use ViewChild and ContentChild in Angular?
Answer: Use @ViewChild to access template elements and child components in the same template. Use @ContentChild to access projected content within a component.
80. How do you implement a custom validator in Angular?
Answer: Create a validator function or a directive that implements Validator interface, and use it in form controls.
81. How do you manage HTTP interceptors?
Answer: Create an HTTP interceptor by implementing the HttpInterceptor interface, and provide it in the providers an array of your module using the HTTP_INTERCEPTORS token.
82. How do you configure internationalization (i18n) in Angular?
Answer: Use Angular’s built-in i18n module, extract translatable strings using ng xi18n, and create locale-specific translation files.
83. How do you use Angular Schematics?
Answer: Use Angular CLI commands to generate code templates and modify projects. You can create custom schematics for reusable code generation.
84. How do you implement nested forms in Angular?
Answer: Create nested FormGroup instances and bind them to form elements in the template using formGroupName directives.
85. How do you use the Renderer2 service in Angular?
Answer: Inject the Renderer2 service into your component or directive, and use its methods to manipulate the DOM in a safe and platform-independent manner.
86. How do you optimize Angular applications for mobile devices?
Answer: Use responsive design techniques, lazy loading, tree shaking, and performance optimization tools like Lighthouse to optimize Angular applications for mobile devices.
87. How do you create a custom Angular library?
Answer: Use the Angular CLI to create a new workspace and generate a library using ng generate library library-name. Develop and publish the library for reuse in other projects.
88. How do you debug Angular applications?
Answer: Use browser developer tools, Angular DevTools, and the ng serve --source-map option to debug Angular applications.
89. How do you handle CORS issues in Angular?
Answer: Configure CORS on the server side or use a proxy in the Angular development environment by setting up the proxy.conf.json file.
90. How do you use Angular’s built-in pipes?
Answer: Apply built-in pipes like DatePipe, CurrencyPipe, UpperCasePipe, etc., directly in your templates using the pipe operator |.
91. How do you handle browser history in Angular?
Answer: Use the Angular Router to manage browser history and navigation. The Location service can also be used for more fine-grained control.
92. How do you implement file upload in Angular?
Answer: Use the FormData object along with HttpClient to send file data to the server. Create a file input element in your template to select files.
93. How do you handle authentication and authorization in Angular?
Answer: Implement authentication using services like Firebase, OAuth, or custom backends, and protect routes using guards. Manage user roles and permissions to implement authorization.
94. How do you create a custom HTTP request header?
Answer: Use the HttpHeaders class to create custom headers and attach them to your HTTP requests using the HttpClient.
95. How do you configure Angular application styles?
Answer: Use global styles in styles.css or styles.scss, component-specific styles in styleUrls, and Angular’s ViewEncapsulation to encapsulate styles.
96. How do you handle cross-component communication?
Answer: Use services to share data between components, event emitters, input/output properties, or state management libraries like NgRx.
97. How do you use the Angular CDK?
Answer: Import Angular CDK modules
