Top Angular 2 Interview Questions and Answers - Essential Guide for Job Seekers

Last updated on Feb 07, 2024
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Angular 2 Interview Questions

To survive in the modern industry and to earn a very good salary, learning only JavaScript programming language is not sufficient, you must move on to learning JavaScript Frameworks also i.e., Angular. It doesn’t matter if you are thinking to start your career in software development or are already a software developer, you will always find Angular 2 Interview Questions useful. This is an open-source component-based UI framework that is written in TypeScript and is mainly used in building web, mobile, and desktop applications in HTML and JavaScript. Angular is an evolved and upgraded version of Angular JS and is invented by Google. For writing codes, Angular provides many language choices like Typescript, Dart, ES5, ES6. It supports both data and property blinding which allows a user to control DOM i.e., Data Object Model by binding class and HTML properties.

Quick Facts About Angular 2
What is the latest version of Angular? Angular 14 released on 2nd June 2022
When did angular 6 release? 14th September 2016
Who is the developer of Angular 2? Google
What language does Angular use? TypeScript
License MIT License
Official website

Frequently Asked Angular 2 Interview Questions for Developers

Here in this article, we will be listing frequently asked Angular 2 Interview Questions and Answers with the belief that they will be helpful for you to gain higher marks. Also, to let you know that this article has been written under the guidance of industry professionals and covered all the current competencies.

Q1. What is the difference between directive and component in Angular 2?
  Components Directive
1. To register, use @Component meta-data annotation To register, use @Directive meta-data annotation
2. Used to create UI widgets and break up app into smaller components Use to design re-usable components and add behavior to existing DOM element.
3. Only one component allowed per DOM element Many directives allowed per DOM element.
4. @View decorator is mandatory Does not use View.
Q2. What is Traceur compiler in Angular 2?

Traceur compiler takes classes, generators, and other features from ECMAScript edition 6 (ES6) and compiles it into JavaScript ES5 that runs on the browser. This means developers can use the code from a future version that has more features and encourages design patterns.

Q3. What is event emitters in Angular 2 and how it works?

Any change that occurs in the component gets propagated from the existing component to its children. If this change needs to be reflected its parent component, you can use using Event Emitter api to emit the event.

EventEmitter is class in @angular/core module that is used by directives and components to emit events.

@output() somethingChanged = new EventEmitter();

You can use somethingChanged.emit(value) to emit any event. You can do this in setter when the value is changed in the class.

Q4. What is string interpolation Angular?

String Interpolation is a special syntax in Angular 2 which is a more efficient alternative to property binding. It is used to display dynamic data on an HTML template while facilitating you to make changes on the component.ts file and fetch data for the HTML template.

Below is an example of a String Interpolation syntax. It should be between double curly braces {{ }} and hence also called a moustache syntax:


class AppComponent
    propertyName: string;
    object: DomainObject;
{{ propertyName }}
{{ object.propertyName }}

Q5. How do you create a custom pipe in Angular?

In Angular 2, you can create custom pipes. The simplest way is as follows.

import { Pipe, PipeTransform } from '@angular/core';
    @Pipe({name: 'Pipename'})
    export class Pipeclass implements PipeTransform {
    transform(parameters): returntype { }

Q6. What is directive in Angular?

Directives are the extended HTML attributes and they are also the most important features of Angular applications. They introduce syntax or markup.

There are 3 kinds of directives-
  • Components
  • Structural
  • Attribute
Q7. What is RouterOutlet in Angular 2?

In Angular 2, the RouterOutlet is a directive present in the router library to be used as a component. It marks the spot in a template for the router to display the components for that outlet.

Every outlet can have its unique name, which is determined by the optional name attribute. The name once set cannot be changed dynamically. If no value has been set, the default value is "primary".


<router-outlet name="left"></router-outlet>

<router-outlet name="right"></router-outlet>

The router outlet emits an activate event during the instantiation of a new component. When the component is destroyed, it is deactivated.

<router-outlet (activate)='onActivate($event)' (deactivate)='onDeactivate($event)'></router-outlet>

Q8. What is dependency injection in Angular?

Angular has a robust DI framework that gives declared dependencies to a class upon instantiation. To inject a service, you must first create and register the injectable service.


import { Injectable } from '@angular/core';
@Injectable({ providedIn: 'root', })
export class SampleService { constructor() { } }

Q9. What is pipes in Angular 2?

In all Angular version from 2 onwards, there is a common feature called Pipes. This feature helps developers create custom pipes.

Pipes are used to write display-value transformations that developers can declare in their HTML. A pipe inputs data and transforms it into the required output.

Pipes in Angular2

There are some pipe provided by angularjs are given below-

  • Uppercase/Lowercase Pipe
  • Date Pipe
  • Currency Pipe
  • JSON Pipe
  • Async Pipe
Q10. How to enable lazy loading in Angularjs?

With lazy loading, JS components can be loaded asynchronously on activation on a specific route.

  • Download and install ocLazyLoad.js
  • Add the module in the application
  • Load the file in the required controller
  • Add to the router’s code as

resolve: {
     loadMyCtrl: ['$ocLazyLoad', function($ocLazyLoad) {return $ocLazyLoad.load('routerState');

Tips to Crack Angular 2 Interview Questions
  • Angular Interviews are not just about learning Java Concepts but one of the toughest questions is to know about software and system designs.
  • Practice is the key factor to crack any type of interview. Angular interviews are no exception too.
  • You should know about basics such as TypeScript, Services, Metadata, Components, etc.
  • If you know about the answer but you are taking too much time to explain it, then that land you nowhere. So yes, Time Yourself i.e. answer your question within a time limit.
  • Teach a concept to your friend or anyone which you have learned. By this, you will know if you learn that concept.
  • Honesty is the best policy. If you don’t know the answer just admit it without wasting the interviewer and your time.
Reviewed and verified by Umesh Singh
Umesh Singh

My name is Umesh Singh having 11+ experience in Node.JS, React JS, Angular JS, Next JS, PHP, Laravel, WordPress, MySQL, Oracle, JavaScript, HTML and CSS etc. I have worked on around 30+ projects. I lo...