Angular fresher interview questions with answers

Here are some Angular fresher interview questions with answers:

What is Angular?

Angular is a web application framework developed and maintained by Google. It is based on TypeScript and uses HTML, CSS, and JavaScript. Angular is used to create single-page applications (SPAs) that are fast, efficient, and easy to maintain.

What are the benefits of using Angular?

There are many benefits to using Angular, including:

• Performance: Angular applications are known for their high performance. This is due to the fact that Angular uses lazy loading to load only the components that are needed for a particular page.

• Scalability: Angular applications are designed to be scalable. This means that they can be easily extended and modified as the needs of the application change.

• Maintainability: Angular applications are easy to maintain. This is due to the fact that Angular uses a well-defined structure and a consistent coding style.

What are the different types of Angular components?

There are three main types of Angular components:

• Directives: Directives are used to add functionality to HTML elements.

• Components: Components are used to create reusable UI elements.

• Services: Services are used to provide data and functionality to components.

What are the different types of data binding in Angular?

There are three main types of data binding in Angular:

• One-way binding: One-way binding is used to bind data from a component to an HTML element.

• Two-way binding: Two-way binding is used to bind data from an HTML element to a component.

• Event binding: Event binding is used to bind events from an HTML element to a component.

What are the different types of routing in Angular?

There are two main types of routing in Angular:

• Lazy loading: Lazy loading is used to load only the components that are needed for a particular page.

• Hashbang routing: Hashbang routing is used to navigate between pages using the URL hash.

What are the different types of forms in Angular?

There are two main types of forms in Angular:

• Template-driven forms: Template-driven forms are created using HTML templates.

• Reactive forms: Reactive forms are created using Angular's reactive forms API.

What are the different types of pipes in Angular?

There are two main types of pipes in Angular:

• Filter pipes: Filter pipes are used to filter data.
• Transform pipes: Transform pipes are used to transform data.

These are just a few of the many Angular interview questions that you may be asked. By preparing for these questions, you can increase your chances of landing your dream job as an Angular developer.

Angular 5 years experience interview questions

Here are some interview questions for candidates with around five years of experience in Angular, along with their answers:

1. Can you explain the concept of Angular Ivy and its benefits?

   • Angular Ivy is the new rendering engine introduced in Angular version 9. It provides several benefits, including:
     • Faster compilation times
     • Smaller bundle sizes
     • Improved debugging and error messages
     • Enhanced template type checking
     • Better performance and runtime efficiency
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2. What is the Angular change detection mechanism and how does it work?

   • Angular's change detection mechanism is responsible for detecting changes in the component's data and updating the user interface accordingly. It works by comparing the previous and current values of the component's properties and triggers a re-rendering of the affected parts of the UI. Angular uses Zone.js and the concept of change detection tree to efficiently track and update changes.
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3. What are Angular directives? Explain the difference between structural and attribute directives.

   • Directives are markers on DOM elements that instruct Angular to perform specific behavior or apply transformations. Structural directives modify the structure of the DOM, such as *ngFor and *ngIf, by adding or removing elements based on conditions. Attribute directives change the behavior or appearance of an element, such as ngStyle or ngClass, by manipulating the element's attributes.
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4. How would you optimize the performance of an Angular application?

   • There are several techniques to optimize the performance of an Angular application, such as:
     • Minifying and bundling the application's code
     • Implementing lazy loading to load modules and components on demand
     • Using AOT (Ahead-of-Time) compilation to reduce the bundle size
     • Implementing efficient change detection strategies (OnPush)
     • Using trackBy function with ngFor for better list rendering performance
     • Optimizing API calls by using caching, pagination, or debounce
     • Employing lazy loading and code splitting for optimal loading times
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5. Explain the concept of Angular forms. What are the different types of forms available in Angular?

   • Angular forms provide a way to capture and validate user input. There are two types of forms in Angular:
     • Template-driven forms: They rely on Angular directives and two-way data binding to handle form data and validation. These forms are easier to set up and suitable for simple scenarios.
     • Reactive forms: They are built using ReactiveFormModule and allow for a more reactive and predictable approach. Reactive forms are suitable for complex scenarios and provide better control over form validation and data handling.
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6. How would you handle cross-origin requests (CORS) in Angular?

   • Cross-origin requests can be handled in Angular by configuring the backend server to allow requests from specific domains. Additionally, Angular provides the HttpClientModule, which automatically sends the required CORS headers with every request. You can also configure proxy settings in the Angular CLI to avoid CORS issues during development.
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7. Explain the concept of Angular services and how they can be shared across components.

   • Angular services are singleton instances that provide a way to share data, state, or functionality across multiple components or modules. Services can be injected into components, other services, or directives using Angular's dependency injection mechanism. By providing services at the root level or using hierarchical injectors, they can be shared and accessed by multiple components throughout the application.
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8. How would you handle routing and navigation in Angular?

   • Angular provides a powerful router module for handling routing and navigation. To set up routing, you define routes in the app-routing.module.ts file, specifying the path, component, and any additional configuration. You can navigate between routes programmatically using the Router service or by using the routerLink directive in HTML templates.
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9. What are Angular decorators and how are they used in Angular applications?

   • Decorators are a feature of TypeScript used in Angular to modify the behavior of classes, properties, methods, or parameters. They are defined using the @ symbol followed by the decorator name. Angular decorators, such as @Component, @Injectable, and @Input, are used to annotate and configure Angular components, services, and directives.
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10. How would you handle asynchronous operations in Angular?

    • In Angular, you can handle asynchronous operations using techniques such as Promises, Observables, or async/await with RxJS. Promises can be used for simple asynchronous tasks, while Observables provide more powerful features like handling multiple values over time, cancellation, and error handling. RxJS operators can be used to transform, filter, or combine Observables.

Angular 2 years experience interview questions with answers

Here are some common interview questions for candidates with around two years of experience in Angular, along with their answers:

1. What is Angular and how does it differ from AngularJS?

   • Angular is a popular TypeScript-based open-source web application framework developed by Google. It is a complete rewrite of AngularJS (Angular 1.x) and introduced several architectural and performance improvements.
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2. What are the key features of Angular?

   • Some key features of Angular include:
     • Two-way data binding
     • Component-based architecture
     • Dependency injection
     • Routing and navigation
     • Reactive forms
     • Observables for handling asynchronous operations
     • Testing support with tools like Jasmine and Karma
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3. Explain the concept of components in Angular.

   • Components are the building blocks of an Angular application. They are responsible for managing a portion of the user interface and its associated logic. A component consists of a TypeScript class, an HTML template, and CSS styles. It encapsulates the data, behavior, and presentation logic related to a specific part of the application.
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4. What is a module in Angular?

   • A module in Angular is a container for organizing related components, services, directives, and other artifacts of an application. It acts as a logical boundary, allowing you to group and organize the different parts of your application. Angular applications are typically built using multiple modules.
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5. Explain the concept of data binding in Angular.

   • Data binding in Angular allows you to establish a connection between the data in your component and the user interface. There are different types of data binding, including:
     • Interpolation: {{ expression }}
     • Property binding: [property]="expression"
     • Event binding: (event)="expression"
     • Two-way binding: [(ngModel)]="property"
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6. What is the role of services in Angular?

   • Services in Angular are used to encapsulate reusable business logic, data manipulation, or communication with external APIs. They provide a way to share data and functionality across different components in an application. Services are typically injected into components or other services using Angular's dependency injection mechanism.
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7. How does lazy loading work in Angular?

   • Lazy loading is a technique in Angular that allows you to load modules and their associated components only when they are needed, rather than loading everything upfront. This helps in improving the initial load time of the application. Lazy loading is achieved by defining separate route configurations for different modules and specifying the "loadChildren" property.
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8. How would you handle HTTP requests in Angular?

   • Angular provides the HttpClient module to handle HTTP requests. To make an HTTP request, you can inject the HttpClient service into your component or service and use its methods like get(), post(), put(), etc. You can also handle request/response interceptors, error handling, and asynchronous operations using observables and RxJS operators.

9. How do you perform unit testing in Angular?

   • Angular provides support for unit testing using tools like Jasmine and Karma. Unit tests are typically written for individual components, services, and other modules. You can use Jasmine's testing functions like describe(), it(), and expect() to define and assert the behavior of your code. Karma is used as a test runner to execute the tests in different browsers.
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10. Explain the Angular CLI and its benefits.

    • The Angular CLI (Command Line Interface) is a powerful tool that helps in scaffolding, developing, and building Angular applications. It provides various commands to generate components, services, modules, and other artifacts of an Angular project. The CLI also helps in managing dependencies, running development servers, running tests, and optimizing the application for production.