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.