Angular Components Interview Questions

This post lists some subjective questions and answers related to Angular components. This collection contains some potential interview questions that may be helpful if you are preparing for a Frontend Engineering job interview specific to Angular framework. Check out Angular Interview Series – Topic Wise Q&A.

1. What is a component in Angular?

A component is a building block of an Angular application that encapsulates and controls a user interface. It consists of an HTML template, a CSS style, and a TypeScript class.

2. How do you create a component in Angular?

We can create a component using the Angular CLI command:

ng generate component component-name

Or in short

ng g c component-name

3. What are decorators in Angular components?

Decorators are functions that modify classes. The @Component decorator is used to define a component, providing metadata such as the selector, template, and styles.

4. What is a template in Angular?

A template is an HTML view that defines how the component will render in the UI. Apart from the plain HTML, Templates in Angular can include Angular-specific syntax for control flow and data binding. Angular does not support <script> element in templates.

5. What is the purpose of the selector in a component?

The selector defines the HTML tag that represents the component in a template. For example, <app-my-component></app-my-component>.

6. What is data binding in Angular components?

Data binding is a mechanism to synchronize data between the component class and the template. It can be one-way (from component to template) or two-way (both ways).

7. What is the difference between @Input() and @Output()?

@Input() allows a parent component to pass data to a child component, while @Output() allows a child component to emit events to a parent component.

8. How do you handle events in Angular components?

You handle events using event binding syntax in the template, like (click)="onClick()", where onClick is a method defined in the component class.

9. What are Lifecycle hooks in Angular components?

Lifecycle hooks are special methods that allow us to tap into key events in a component’s lifecycle, such as ngOnInit, ngOnChanges, ngOnDestroy etc.

10. What is the purpose of ng-content?

ng-content is used for content projection, allowing us to insert and display content from a parent component into a child component’s template.

11. What are standalone components in Angular?

A Standalone component is self-contained, reusable unit of code that is not part of any Angular module. Standalone components are designed to be independent and can be shared across multiple Angular applications.

• Unlike regular components, standalone components are not dependent on Angular’s NgModule system for their configuration and dependencies.
• Standalone components were introduced in Angular 14. From Angular 17+, Standalone component is the CLI default.

12. How do you create a standalone component in Angular?

To create a standalone component in Angular, we can use the ng generate component command with the --standalone flag.

These are a few questionnaires specific to Angular Components. I will be adding more questions and answers to this post. To know more details please refer to the Official documentation on Angular Components.