#Angular

Last updated    - V7 (19-Dec-2025)

Key Concepts

S.No	Topic	Sub-Topics
1	Introduction to Angular	What is Angular, Features, Advantages, Angular vs AngularJS, Use cases
2	Angular Architecture	Modules, Components, Templates, Services, Dependency Injection, Directives
3	Setting up Angular	Node.js installation, Angular CLI, Creating new project, Project structure, Running app
4	TypeScript Basics	Variables, Types, Functions, Classes, Interfaces, Decorators
5	Components	Creating component, Component decorator, Template, Styles, Lifecycle hooks
6	Templates & Data Binding	Interpolation, Property binding, Event binding, Two-way binding, Template reference variables
7	Directives	Structural directives, Attribute directives, ngIf, ngFor, Custom directives
8	Pipes	Built-in pipes, Custom pipes, Chaining pipes, Async pipe, Date and number formatting
9	Services & Dependency Injection	Creating service, Injectable decorator, Singleton service, Using service in component, Hierarchical injection
10	Routing & Navigation	RouterModule, Routes configuration, RouterLink, Route parameters, Lazy loading
11	Forms in Angular	Template-driven forms, Reactive forms, FormControl, FormGroup, Validators
12	HTTP Client	HttpClientModule, GET request, POST request, Handling errors, Interceptors
13	Observables & RxJS	Observable creation, Subscribing, Operators, Subjects, Async data handling
14	Routing Guards	CanActivate, CanDeactivate, CanLoad, AuthGuard example, Route protection
15	Angular Modules	NgModule, Feature modules, Shared modules, Core module, Lazy-loaded modules
16	Angular CLI Commands	ng generate, ng serve, ng build, ng test, ng lint
17	Angular Animations	Trigger, State, Transition, Animate, Keyframes
18	Angular Material	Installing Angular Material, Material components, Theming, Buttons & icons, Responsive layout
19	Unit Testing	Karma, Jasmine, TestBed, Component testing, Service testing
20	End-to-End Testing	Protractor, Cypress, Writing e2e tests, Running tests, Best practices
21	Change Detection	Zones, Default strategy, OnPush strategy, DetectChanges, MarkForCheck
22	Angular Lifecycle Hooks	ngOnInit, ngOnChanges, ngDoCheck, ngAfterViewInit, ngOnDestroy
23	Angular Security	Sanitization, XSS prevention, Content Security Policy, Authentication, Authorization
24	State Management	Services for state, RxJS BehaviorSubject, NgRx overview, Actions & Reducers, Store usage
25	Lazy Loading & Preloading	Lazy-loaded modules, PreloadAllModules, Route configuration, Performance benefits, Example setup
26	Angular Interceptors	HttpInterceptor, Logging requests, Adding headers, Error handling, Token authentication
27	Custom Structural & Attribute Directives	Creating directive, HostListener, HostBinding, Manipulating DOM, Examples
28	Angular Internationalization (i18n)	i18n setup, Translating text, Dynamic locale, Date & number formatting, Building for multiple languages
29	Performance Optimization	ChangeDetectionStrategy, Lazy loading, TrackBy in ngFor, OnPush strategy, Ahead-of-Time compilation
30	Hands-on Project	Create Angular app, Use routing, Forms & HTTP, Services & DI, Deploy and optimize

Interview question

Basic Level

1. What is Angular and why is it used?
2. Difference between Angular and AngularJS.
3. Features of Angular.
4. Advantages of using Angular.
5. What is TypeScript and why Angular uses it?
6. What is Angular CLI?
7. How to create a new Angular project using CLI?
8. What is a component in Angular?
9. Explain the structure of an Angular project.
10. What are templates in Angular?
11. What is data binding in Angular?
12. Types of data binding in Angular.
13. What is interpolation?
14. What is property binding?
15. What is event binding?
16. What is two-way binding?
17. What are directives in Angular?
18. Types of directives in Angular.
19. What is a pipe in Angular?
20. Built-in pipes in Angular.
21. How to create a custom pipe?
22. What are modules in Angular?
23. What is NgModule?
24. What is dependency injection in Angular?
25. What are services in Angular?

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Intermediate Level

1. What are Angular lifecycle hooks?
2. Explain ngOnInit, ngOnChanges, ngOnDestroy.
3. What is the difference between structural and attribute directives?
4. What is the difference between *ngIf and [hidden]?
5. Explain ngFor and trackBy.
6. What is Angular routing?
7. How to configure routes in Angular?
8. How to pass route parameters?
9. What are route guards?
10. Types of route guards.
11. What is lazy loading in Angular?
12. What is preloading in Angular?
13. How to handle forms in Angular?
14. Difference between template-driven and reactive forms.
15. Explain FormControl, FormGroup, and FormArray.
16. How to implement form validation?
17. Built-in validators in Angular.
18. How to create custom validators?
19. How to make HTTP requests in Angular?
20. What is HttpClientModule?
21. How to handle HTTP errors?
22. How to use interceptors in Angular?
23. What are observables in Angular?
24. How to use RxJS operators?
25. Difference between promises and observables.

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Advanced Level

1. What is Angular change detection?
2. How does Angular detect changes in components?
3. What is ChangeDetectionStrategy.OnPush?
4. What is a zone in Angular?
5. Difference between default and OnPush change detection.
6. What are Angular animations?
7. How to implement animations using Angular?
8. What is Angular Material?
9. How to use Angular Material components?
10. How to implement responsive design in Angular?
11. What is Ahead-of-Time (AOT) compilation?
12. What is Just-in-Time (JIT) compilation?
13. Difference between AOT and JIT.
14. How to optimize Angular performance?
15. What is a singleton service?
16. How to provide services in root vs component?
17. What is Angular injector hierarchy?
18. How to use HostBinding and HostListener?
19. How to create custom structural directives?
20. How to create custom attribute directives?
21. How to handle i18n (internationalization) in Angular?
22. How to use Angular pipes for i18n?
23. What are dynamic components?
24. How to create dynamic components using ComponentFactoryResolver?
25. How to handle file uploads in Angular?

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Expert Level

1. How to implement state management in Angular?
2. What is NgRx and why use it?
3. How to implement actions, reducers, and selectors in NgRx?
4. How to use BehaviorSubject for state management?
5. How to implement server-side rendering with Angular Universal?
6. How to integrate Angular with a REST API backend?
7. How to secure Angular applications?
8. How to implement authentication and authorization in Angular?
9. How to implement JWT token authentication in Angular?
10. How to integrate Angular with OAuth2/OpenID Connect?
11. How to implement route-based lazy loading for modules?
12. How to handle caching strategies in Angular?
13. How to implement service workers and PWA with Angular?
14. How to test Angular applications using Jasmine?
15. How to write unit tests for components, services, and pipes?
16. How to write end-to-end tests using Protractor or Cypress?
17. How to optimize Angular bundle size?
18. How to implement code splitting in Angular?
19. How to integrate Angular with CI/CD pipelines?
20. How to deploy Angular applications to production?
21. How to handle memory leaks in Angular applications?
22. How to debug Angular performance issues?
23. How to monitor Angular applications in production?
24. Best practices for Angular application architecture.
25. Best practices for Angular security and performance.

Related Topics

#ReactJS

Last updated    - V7 (14-Dec-2025)

Key Concepts

S.No	Topic	Sub-Topics
1	Introduction to React	What is React, SPA Architecture, Virtual DOM, React Features, Prerequisites
2	Environment Setup	Node & npm, Create React App, Folder Structure, Dev Server, Basic App
3	JSX Basics	JSX Syntax, Embedding Expressions, Babel, JSX Rules, Differences from HTML
4	Components	Functional Components, Class Components, Props Basics, Component Reuse, Composition
5	Props & State	Props Usage, Passing Data, useState Hook, State Definition, State vs Props
6	Event Handling	Event Basics, Synthetic Events, Event Binding, Passing Params, Event Objects
7	Conditional Rendering	If/Else, Ternary, Logical &&, Conditional Component, Fragments
8	Lists & Keys	Dynamic Lists, Array.map(), Key Importance, Nested Lists, List Styling
9	Forms	Controlled Components, Uncontrolled Components, Submit Handler, Text Inputs, Form Validation
10	useEffect Hook	Effects Intro, Dependency Array, Cleanup, API Calls, Multiple Effects
11	React Router	Router Setup, Routes, Link & NavLink, URL Params, Navigate
12	Context API	CreateContext, Provider, useContext, Avoid Props Drilling, State Sharing
13	Custom Hooks	Why Custom Hooks, Rules, Business Logic Hook, Reusable Hook, useFetch
14	Performance Optimization	React.memo, useMemo, useCallback, Batching, Re-render Control
15	State Management	Lifting State, Global Store, Redux Intro, Reducer, Actions Flow
16	Redux Toolkit	RTK Install, createSlice, Store Setup, Provider, Dispatch & Selector
17	Async Operations	Axios, Fetch API, Async/Await, Error Handling, Loading States
18	Error Boundaries	Fallback UI, Logging, Try/Catch, Boundary Component, Debugging
19	Optimization II	Profiler, Pure Components, Code Splitting, Lazy Loading, Tree Shaking
20	Testing	Jest Basics, RTL Intro, Mocking API, Unit Tests, Snapshot Testing
21	Advanced Patterns	HOC Pattern, Render Props, Compound Components, Provider Pattern, Hooks Composition
22	React with TypeScript	TS Setup, Props Typing, State Typing, Custom Types, Interfaces
23	Styling	CSS Modules, Styled Components, Tailwind CSS, Material UI, Chakra UI
24	Authentication	Login Flow, JWT Token, Protected Routes, Session Storage, Role-Based UI
25	Deployment	Build App, Netlify, Vercel, GitHub Pages, Environment Config
26	Next.js Basics	SSR, SSG, Routing, Layouts, API Routes
27	Architecture	Folder Structure, Atomic Design, Feature Based Structure, Clean Code, Service Layer
28	Best Practices	DRY Principle, KISS, Performance Tips, Error Handling, Security
29	Project Development	UI Planning, Component Design, Data Flow, State Logic, Router + Redux
30	Final Review	Code Cleanup, Documentation, Testing Coverage, Refactor, Deployment

Interview question

Basic Level

1. What is ReactJS?
2. What is the difference between React and Angular?
3. What is JSX in React?
4. Why do we use JSX instead of JavaScript?
5. What is a component in React?
6. What is the difference between functional and class components?
7. What are props in React?
8. What is state in React?
9. Difference between state and props?
10. What is Virtual DOM in React?
11. Explain the concept of one-way data binding.
12. What is create-react-app?
13. What is the purpose of render() method?
14. What are lifecycle methods in React?
15. What is a controlled component?
16. What is an uncontrolled component?
17. How do you handle events in React?
18. What are fragments in React?
19. What is the purpose of key in React lists?
20. What is conditional rendering?
21. How do you update the state in React?
22. What is React Router?
23. What is context API?
24. What are hooks in React?
25. What is useState hook?

Intermediate Level

1. What is useEffect hook used for?
2. Difference between useEffect and lifecycle methods?
3. What causes a re-render in React?
4. What is prop drilling?
5. How to avoid prop drilling?
6. What is useContext hook?
7. What are custom hooks?
8. What is memoization?
9. What is React.memo?
10. What is useMemo hook?
11. What is useCallback hook?
12. Difference between useMemo and useCallback?
13. How do you fetch data in React?
14. What is axios?
15. What is lazy loading?
16. What is error boundary?
17. What is suspense in React?
18. Explain code splitting in React.
19. What is ReactDOM?
20. Difference between JSX and HTML?
21. What are controlled inputs?
22. How do you share data between siblings?
23. What is Context Provider and Consumer?
24. What is Redux?
25. How do you implement routing?

Advanced Level

1. What is Redux architecture?
2. What are actions in Redux?
3. What are reducers in Redux?
4. What is a Redux store?
5. What are middleware in Redux?
6. What is Redux Thunk?
7. Difference between Redux Thunk and Saga?
8. What is createSlice in Redux Toolkit?
9. What is immutability in React?
10. How do you optimize performance in React?
11. What is reconciliation algorithm?
12. What is hydration?
13. What is Render Props pattern?
14. What are Higher Order Components (HOC)?
15. What are compound components?
16. Context vs Redux?
17. What is SSR in React?
18. What is SSG?
19. What are API routes in Next.js?
20. What is hydration mismatch?
21. What is StrictMode in React?
22. What is priority rendering?
23. Explain batching in React.
24. What are portals in React?
25. What is tree-shaking?

Expert Level

1. How does React?s Fiber architecture work?
2. Explain the reconciliation algorithm in depth.
3. Difference between useLayoutEffect and useEffect?
4. What is concurrent mode in React?
5. Explain React render phases (render/commit).
6. How do you build reusable component libraries?
7. Explain micro-frontends with React.
8. What is React Profiler?
9. How do you debug performance issues?
10. SSR vs CSR?
11. Explain static site generation use-cases.
12. How does React work internally with DOM?
13. Rules of React Hooks?
14. How to create custom middleware in Redux?
15. Explain observer pattern in React.
16. Difference between context selector and global state?
17. Explain atomic design architecture.
18. How to optimize React app for SEO?
19. How do you avoid unnecessary re-renders?
20. How does Suspense work internally?
21. Explain state normalization.
22. Explain Flux architecture in detail.
23. How do you handle error logging in production?
24. How do you structure large enterprise React apps?
25. Explain distributed state management in complex applications.

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