What are the Top 20 Angular Interview Questions and How to Prepare for Them

In this blog we provide a curated list of the top 20 Angular interview questions, along with tips and strategies on how to prepare for them. Whether you’re a beginner or experienced Angular developer, this resource will help you build confidence and increase your chances of facing your next interview.

Billions of people use web and smartphone apps for everything from social networking, health care, e-commerce, and online banking. These apps provide simple user interfaces and experiences that assist us daily. How are these programs designed to be trusted? Part of the credit goes to frameworks like Angular, which make it simple to create functional apps.

What is Angular?

Angular is a JavaScript framework written in TypeScript that is open source and free to use. Google maintains it, and it is mainly used to create single-page apps. Angular is a framework with undeniable advantages. It also provides programmers with a consistent framework in which to operate. It enables people to develop large apps in an easy-to-manage manner.

In this article we have prepared some frequently asked Angular Interview Questions for applicants with experience from up to two to more than seven years.

Questions and Answers for Interview Preparation 

  1.  What kinds of technologies are used by Angular?

Google made the cutting-edge front-end framework Angular, which uses JavaScript. Angular uses TypeScript. TypeScript lets us write JavaScript as a strictly typed language and specify our types. This makes it easier to find bugs. RxJS makes it easier to manage processes that run in parallel.

  1. What are the different versions of angular?

Angular 1 was the first version, which later became AngularJS. Next came Angular 2, 3, 4, and 5; finally, on November 11, 2020, Angular 11 came out. 

  1. What is TypeScript?

Most front-end developers like that Angular can be used with TypeScript. TypeScript makes finding errors easy and compiling errors by automatically filling in the blanks. It also has robust interfaces, access controls, hybrid types, etc. All of these lead to a shorter development time when they work together.

  1. Draw a picture of Angular architecture.

Here are the parts that makeup Angular architecture. 

  • NG Modules  
  • Components and Templates
  • Data Binding 
  • Directives 
  • Services 
  • Metadata
  • Dependency Injection
  1. How is the constructor different from the ngOnInit?

The list below shows the differences between the constructor and ngOnInit:

  • Objective.

Constructor :- The goal of a constructor is to set up class members.

NgOnlnit :- OnInit stops things from working in builders when starting up or making a public announcement.

  • Usage

Constructor :- A constructor should be used to set up Dependency Injection, initialize class fields, etc.

NgOnlnit :- In ngOnInit, you write the working code that starts running as soon as the class is created.

  1. What is the purpose of the ngFor directive?

When a component or parts of an HTML template must be repeated for each item in a collection, the ngFor directive can be utilized. In essence, it employs the ngFor directive to create a template for each iteration as it becomes easier.

  1. What is the purpose of the ngIf directive?

The ngIf directive’s objective is to destroy or rebuild a section of the DOM tree based on an expression. If the ngIf directive detects that the condition is false, the element is removed from the tree; otherwise, a matched element is added to the DOM tree.

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  1. What happens when a script tag is used within a template?

When a script tag is used within a template, Angular flags the value as unsafe and initiates the sanitization process. This removes the script tag while preserving the text element’s content. As a result of the entire process, the threat of injection attacks is eradicated.

  1. What exactly do template expressions mean?

A template expression in Angular is an expression that returns a value and is enclosed in double curly brackets. Angular executes the template expression and applies it to a binding’s target property. An HTML element, a directive, or even a component can now be used as the binding target.

  1. How do template statements function?

“Template statements” in Angular are HTML actions or elements used to respond to “consumer events.” These template statements allow your app to engage users by allowing them to perform things like display dynamic information or fill out forms.

  1. . How is Angular different from AngularJS?

Some of the most notable differences between Angular and AngularJS are as follows:

  • Architecture 

Angular :- Components and directives are used.

AngularJS :- As a model language, Model-View-Controller, or MVC, is supported.

  • Language 

Angular :- It makes use of TypeScript, which is a superset of statistically typed JavaScript.

AngularJS :- It employs the dynamically typed programming language JavaScript.

  • Syntax

Angular :- Angular uses () to bind an event and [] to bind a property.

AngularJS :- To bind a property or event, experts must use the appropriate ng directive.

  • Mobile Support 

Angular :- Mobile devices are supported by Angular.

AngularJS :- Unlike Angular, AngularJS does not support mobile.

  1. What are the benefits of Angular?
Top 20 Angular Interview Questions and Answers

Utilizing Angular offers several advantages, which we will mention below:

  • Since Angular is built with TypeScript, programmers may write strongly typed code that will be converted into JavaScript. Strongly typed code is easier to read, easier to work with, and less likely to have errors. It also provides more useful tools, such as type suggestions and code completion.
  • Angular allows us to organize our code into modules that may be used to house functionality linked to a specific activity, such as HTTP connection, data validation, routing, and so on.
  • A wide ecosystem of Angular’s tools, libraries, frameworks, plugins, and other components makes the development process more efficient and effective overall. RxJS, NgRx, Angular CLI, and other programs and libraries are among them.
  1. What are the various methods for binding data?

In Angular, there are numerous types of data binding. The following are the several types of data binding in Angular:

  • One Way Data Binding
  • Two-Way Data Binding: 

There are numerous types of two-way data binding.

  • Interpolation
  • Property binding
  • Class binding
  • Style binding
  • Attribute binding
  • Event binding
  • Two-way binding
  1. What is the purpose of the async pipe?

The async pipe marks the bits that must be checked for changes. It returns the most recent value it sends out and matches an Observable or Promise. When this new value is emitted, the async pipe notifies you of the changes. 

Similarly, if the component’s expression reference changes, the async pipe unsubscribes from the previous Observable or Promise and subscribes to the new one.

  1. What exactly is a pipe with parameters?

Parameterized pipes are pipelines that contain parameters. We can pass unlimited parameters through these pipes by including a colon (:) in the command.

  1. What exactly is a customized pipe?

You may create one-of-a-kind pipelines using Angular. In Angular, they used to be called “Filters,” but now they’re just specialized pipelines.

  1. How do custom elements function?

You can create a tag whose content is created and managed by JavaScript code by adding a custom element to HTML.

  1. What exactly is a starting point module?

The “Bootstrapping Module” in Angular is the root module to launch the application. A Bootstrapping Module is a subclass of the AppModule class found in all Angular programs. The Bootstrapping module is also known as the AppModule.

  1. Is it necessary to employ custom Bootstrap elements?

No, we don’t need to bootstrap custom elements because they do it automatically when introduced to the DOM.

  1. Provide an example of how to utilize HttpClient.

The following are the general steps for using the HttpClient:

  • Begin by establishing a HttpClient object.
  • Next, make an instance of any of the methods.
  • To run the method, use the HttpClient command.
  • Read the response after the execution.
  • Lastly, disconnect the connection.
  • And then deal with the reaction.


Thus, these are the top 20 Angular Interview questions and answers which can be helpful in interview preparations for both beginners as well as professionals.

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