Top 150 Angular Interview Questions and Answers

Components are building blocks of Angular applications, while directives are used to add behavior to DOM elements.

• Components have a template, styles, and behavior encapsulated together, while directives are used to manipulate the behavior of existing...read more

Performance issues in Angular can be handled by optimizing code, reducing HTTP requests, and using lazy loading.

• Optimize code by using trackBy in ngFor loops

• Reduce HTTP requests by using caching and pagination

• Use lazy loading to load only necessary c...read more

Angular has four types of data bindings: Interpolation, Property binding, Event binding, and Two-way binding.

• Interpolation: {{ expression }}

• Property binding: [property]="expression"

• Event binding: (event)="expression"

• Two-way binding: [(ngModel)]="expr...read more

Yes, I am proficient in React and have experience working with Angular as well.

• Proficient in React for building user interfaces

• Experience working with Angular for front-end development

• Familiar with component-based architecture in both React and Angul...read more

The @Input() and @Output() are decorators in Angular used for communication between parent and child components.

• The @Input() decorator is used to pass data from a parent component to a child component.

• The @Output() decorator is used to emit events fr...read more

Business logic, presentation logic, and service logic can be separated using Angular's component architecture.

• Create separate components for each logic layer

• Use services to handle business logic

• Use pipes for presentation logic

• Keep components simple a...read more

To call REST APIs in Angular, use the HttpClient module and its methods like get(), post(), put(), delete().

• Import the HttpClientModule in your Angular module

• Inject the HttpClient service in your component or service

• Use the HttpClient methods to make...read more

Angular Interceptor is a middleware that intercepts HTTP requests and responses.

• It can be used to add headers, modify requests, handle errors, and more.

• Interceptors can be global or specific to a certain request.

• Example use cases include adding authe...read more

Angular Components are the building blocks of Angular applications.

• Components are reusable and self-contained

• They have a template, styles, and logic

• They can communicate with other components using @Input and @Output decorators

• Examples include navbar,...read more

To set up the environment for building an Angular application, you need to install Node.js and Angular CLI.

• Install Node.js and npm

• Install Angular CLI using npm

• Create a new Angular project using CLI

• Run the project using ng serve command

Template driven forms are based on directives while reactive forms are based on reactive programming.

• Template driven forms are easier to use and require less code.

• Reactive forms are more flexible and allow for more complex validation.

• Template driven ...read more

Pipes are used to transform data in templates, while directives are used to manipulate the DOM.

• Pipes are used to format data in templates, such as date formatting or currency conversion.

• Directives are used to add behavior to DOM elements, like hiding...read more

Components in Angular can communicate with each other using @Input, @Output, and services.

• Use @Input to pass data from parent to child component

• Use @Output to emit events from child to parent component

• Use services to share data between components tha...read more

Custom directives in AngularJS allow you to create reusable components.

• Create a new directive using the directive() method

• Specify the directive's behavior using the link() method

• Use the directive in HTML using its name as an attribute

• Pass data to the...read more

Angular life cycle hooks are methods that allow you to tap into specific points in a component's life cycle.

• ngOnChanges: called when an input property changes

• ngOnInit: called once after the first ngOnChanges

• ngDoCheck: called during every change detec...read more

Building blocks in Angular are components, directives, services, and modules.

• Components are the basic building blocks of Angular applications.

• Directives add behavior to an existing DOM element or component.

• Services are used to share data or logic acr...read more

Angular directives are markers on a DOM element that tell AngularJS to attach a specified behavior to that DOM element.

• Directives are used to create custom HTML tags that serve as new, reusable widgets.

• They can be used to manipulate the DOM, add even...read more

ng-content is a directive in Angular that allows for dynamic insertion of content.

• It is used to project content into a component from the outside.

• It is often used in combination with ng-template and ng-container.

• It can be used to create reusable comp...read more

ngFor is a directive in Angular used for iterating over a collection of data and rendering it in the UI.

• ngFor is used in Angular templates to display a list of items by iterating over an array or object.

• It is commonly used with an *ngFor directive in...read more

Use Angular's 'resolve' property to load component after services are loaded.

• Create a resolver service that waits for all three services to complete before resolving.

• Add the resolver service to the 'resolve' property of the component's route.

• Access t...read more

Angular is a front-end framework for building client-side applications, while Node.js is a back-end runtime environment for running server-side applications.

• Angular is used for building dynamic web applications with HTML, CSS, and TypeScript.

• Node.js ...read more

Angular Routes are used to navigate between different components and views in an Angular application.

• Routes are defined in the app-routing.module.ts file

• Each route maps a URL path to a component

• Routes can have parameters and child routes

• Navigation be...read more

Implement security in Angular by using built-in features like Angular Router Guards, HTTP Interceptors, and secure coding practices.

• Use Angular Router Guards to control access to routes based on user authentication and authorization.

• Implement HTTP In...read more

Optimizing an Angular project involves reducing bundle size, lazy loading modules, using AOT compilation, and optimizing performance.

• Reduce bundle size by removing unused code and dependencies

• Lazy load modules to only load components when needed

• Use A...read more

The design pattern commonly used in Angular is the Observer pattern.

• The Observer pattern is used to establish a one-to-many dependency between objects.

• In Angular, Observables are used to implement the Observer pattern for handling asynchronous data s...read more

Angular life cycle is a series of events that occur from the creation of a component to its destruction.

• ngOnChanges - called when an input property changes

• ngOnInit - called once after the first ngOnChanges

• ngDoCheck - called during every change detect...read more

Angular Architecture is a structural design of Angular applications that includes components, modules, services, and routing.

• Angular applications are built using components, which are reusable building blocks with their own logic and templates.

• Module...read more