Angular 4 interview questions and answers | Complete 2020 guide

Angular is an open source web development framework that Google develops and maintains. It combines declarative templates, end-to-end tools, injection dependency and integrated best practices to solve challenges for development. It is constantly updated to improve usability and increase the productivity of the developer. In this article, we will know to learn all about angular 4 interview questions.

What’s angular 4, then? In recent years, Angular has developed rapidly into newer versions, from versions 1.0 (AngularJS) to Angular 2 and 4. Angular 4 was released in March of 2017 and has further versions of Angular. It’s a front-end web application platform based on TypeScript.

Content flow hide
1 Angular 4 interview questions and answers
1.7 Top 50 angular 4 interview questions

Angular 4 interview questions and answers

Before we show you the Angular 4 interview questions and answers, lets first understand about angular 4.

Features of Angular 4

Angular 4 is an improvement on Angular 2, it has a different architecture altogether. In addition to earlier angular versions, the features of Angular 4 include:

1. Compatibility with Typescript 2.1+

Angular 4 supports TypeScript ‘s latest versions, i.e. 2.1 and 2.2, respectively. This improved the ngc rate and enabled superior type inspection.



In angular 4, adding search parameters to the HTTP request is easier.


3.*nglf and* ngFor improved

In angular 4, a if / else design syntax can be used in your templates. You can also allocate a local variable, like unrolling an observable.


4. A new view engine that generates less code in AoT mode

Unlike the” just in time” mode, in which template compilation is performed during runtime, the AoT mode template compilation takes place during building and the JS code is generated subsequently. This has several advantages, including finding out whether your template is incorrect at the time of construction.

However, the downside to AOT is that the generated JS code is generally larger than the uncompiled HTML template. In Angular 4, the viewing engine was improved to reduce the code generated by about 60 percent using AOT mode.


5. Animation

Animations were pulled from the angular core in Angular 4 and packaged into a standalone animation module. If you don’t have to use animations, this excess code must not be included in your creation packages. You can import the browser animation module from @angular / platform-browser / animations to add animations to the main NgModule.


6. Pipes

In Angular 4,t he pipe oscillates the first letter of each word into Uppercase.


7. Router

Angular 4 uses ParamMap instead of parameters or query parameters to represent URL parameters.


8. New plugin SystemJS

This plugin converts ” component related ” paths dynamically to ” absolute paths ” in styleUrls and template URLs.

Angular 4 interview questions and answers

Benefits of Angular 4

Because it is the latest version of the Angular Framework, Angular 4 has more powerful features and capabilities to create complex, modern, customizable, responsive and user-friendly web applications for developers.

Some of the advantages include:


1. Generation of codeAngular 4 interview questions and answers

Angular transforms your templates into code that is greatly increased for today’s virtual JavaScript machines, combining the benefits of handwritten code with the productivity of a framework.


2. Splitting of Code

The new Angular component router automatically splits the code so that users only load the required code to render the view they want. This increases the load speed of Angular applications.


3. Progressive web applicationsAngular 4 interview questions and answers

Angular uses modern web platforms to deliver app like experience.


4. Cross-platform desktop applications

Angular allows developers to create cross platform applications installed on the desktop.


5. Mobile app development

Angular makes it easier to create native mobile apps using React Native, Native Script and Ionic Framework strategies.


6. Templates

Angular allows user views to be created quickly with a powerful yet simple template syntax.


7. Create applications that are accessible

You can create accessible applications using developer guides, ARIA-enabled components and integrated test infrastructure in Angular.


8. Animation

 The intuitive API of Angular allows developers to create complex, high-performance choreographies and animation schedules with minimal code.


9. IDE

Developers can receive instant error reports, smart code completion and other feedback.


10. The interface of Angular Command Line (CLI)

With the command-line tools of Angular, developers can build, add components, test and deploy in a very short time.


Tutorial by Codevolution


How will angular 4 help in your career?

As the successor of the extremely successful AngularJS, Angular 4 is bound to be the future of development at the front end. The importance of learning Angular cannot be stressed enough for web developers and mobile app developers–and it is only sensible to learn the latest version: Angular 4.

This is true whether you are already working in the field and whether you want to maintain your skills (current and relevant) or just get started. This is how learning Angular 4 in your career can have a positive impact.


1. Angular ‘s growing popularity

Angular follows a sturdy versioning model as a Google product. The Angular team always works to fix bugs and add better functionality to each new version. Knowing the latest version positions that you have updated technologically and preparing you to learn the next version soon after its release.


2. Increasing demand for skilled developers

Angular is a complete rewrite of AngularJS and new versions will have to be adopted by companies. Since the Angular 4 is still relatively new, there are few developers in the market. Learning it now would make you one of the few developers you are looking for.


3. Massive pay packages for developers of Angular

The pay is high due to the scarcity of angular developers. This makes Angular 4 a very profitable skill to master.


Angular 4 interview questions and answers


How to prepare for angular 4 interview questions and answers

  • AngularJS, popularly known as the ” Swiss Army Knife ” in the developer community, has seen growth in career opportunities in recent years. The AngularJS framework is known to create customizable web applications that are highly user-friendly.
  • The three key points behind the successful application of AngularJS are speed, agility and strong community support. AngularJS has been dominating the JavaScript frame area for a long time. And it is known to be one of the ROIs generated by web developers for their career growth.
  • The career path of AngularJS is therefore unquestionably challenging, but extremely gratifying and therefore fulfilling.
  • Honestly, coming to the main part of cracking angularJS interview questions is not an easy task. Frankly, it’s pretty hard, but if you follow a strategy. And it’s not an impossible task to prepare questions for the interview beforehand. But you have to plan well for the same.
  • You may have participated in a number of tutorials in which you learned the basics and almost everything about angular JS. But to get out of angularJS interview questions successfully, you need to go deeper. It is mostly observed that interviewees do not make such a specific set of questions that you will receive during your interview. The questions may be pretty random, but the idea is to check your principles. Thus, repeatedly revise your basics.
  • Don’t expect any questions about rocket science, as the person sitting on the other side of the table knows that you have asked the toughest questions, but what needs to be checked is that you have sound knowledge of the framework. Is the basics of your Angular is strong? You must also remember that you have to be up front about what you know and what you don’t know while attending an angular interview.
  • Don’t try to bluff people around you as they immediately understand your depth in the Angular field. Therefore, if you have questions you don’t know, tell them you don’t know and trust us, they will appreciate this and try to teach you.
  • What will help you to break an interview with Angular is not your ” Know All ” attitude but your willingness to learn new developments in Angular.
  • A very important point to note here is that the web world is evolving very rapidly. Every second there are new and overnight developments. You are not expected to learn everything, therefore. Just make sure you know the basics correctly and show an attitude towards learning new things. It’s what takes you forward. Focus on your personality and learn about Angular Interview Questions and answers. Don’t ever try to mug the whole thing, as this will lead to confusion and unnecessary nervousness in the last minute.

Keep the above tips in mind and attend the interview with confidence!!!


Also Read:-

Recommended Book


Basic interview questions on Angular 4

Below given are few basic interview questions of Angular 4 which is commonly asked to beginners:

1. What are binding in Angular 4 and different binding types?

Answer: The binding process in Angular 4 is a process for synchronizing the view and the model components that are different layers in the application. The data binding feature is available since Angular 2.

The various types of binding are –

  • Two-way binding
  • Property and
  • Event binding

This binding of data is the key and important factor in angular components.

Two-way binding is the combination of Event binding and Property binding functions where Event binding is defined as the process to update the values of a variable or attribute from the View component layer to the Model Component Layer and Property Binding is defined as the process to update the variable or attribute in the Model component and display the values in the View component.


2. What’s the difference in between components and directives?

Answer: The Angular 4 components are defined as the basic classes that interact with web page components like html files or UI elements. The components using Decorators are defined as components. Each and every component is predefined by a template. Using an angular directive, a class can be defined to make it a directive that can be used by processing and installation at runtime.


3. What is typescript and how is it useful for Angular 4?

Answer: Typescript is a general programming language developed by Microsoft and a subset of the programming language of JavaScript. Angular 4 frame is built entirely on Typescript language. Typescript is a primary language used in Angular and can be used to develop angular apps and the code is later transposed to support multiple or different versions of browser platforms using transpires.


4. What are angular 4 components?

Answer: This is the common question of the Angular 4 that are asked in an interview. The Angular 4 components are defined as the basic classes that interact with web page components such as HTML files. The components using Decorators are defined as components. Each and every component is predefined by a template. Using @Component, called Decorator, a component can be defined. The selector, style and template can be defined to implement the additional functionality within the component.


5. What are the Angular 4 modules?

Answer: An Angular module is defined as the file in which all the directives, components, pipes and services are grouped together to make it a perfect angular application. Each Angular app has a root module that is defined in the Typescript file format app.module.ts. NgModule can be used to define a module in Angular 4.


Top 50 angular 4 interview questions

Below given are top 50 angular 4 interview questions that have to be mastered before going for an interview:

1.       What Are Angular 4?

2.       What Is Angular?

3.       What’s New in Angular 4?

4.       How to Setup Angular 4 Development Environment?

5.       What Is Architecture Overview of Angular?

6.       What Is a Template Reference Variable?

7.       What Is Bootstrapping in Angular?

8.       What Are the Differences Between Angular and Angular Js?

9.       What is AOT Compilation?

10.   How to share global data across components?

11.   What is ng-components in Angular 4?

12.   What is ng-modules in Angular 4?

13.   What is @output In Angular?

14.   What is @inputs In Angular?

15.   What are pipes in Angular 4?

16.   What is lazy loading?

17.   What is Change detection?

18.   What is ECMA Script?

19.   What are Directives in Angular 2/4?

20.   What Are Event Emitters in Angular 2/4?

21.   What is dependency injection in angular 2/4?

22.   What are services in Angular 2/4?

23.   What are typing in Angular 2/4?

24.   What is Webpack for angular 2?

25.   What is Transpiling in Angular?

26.   What is a Router Outlet?

27.   What does a Subscribe method do in Angular 4?

28.   Explain component decorators in Angular4.

29.   Write the CLI command to generate a component in Angular4.

30.   Explain the component directory structure of angular4.

31.   Explain ngFor directive with an example.

32.   Explain property binding or one-way binding in angular js.

33.   Explain ngIf directive with an example.

34.   Write the difference between directive and component in angular js.

35.   What do you understand by Isolated Unit Tests?

36.   What is a routing in angular js?

37.   What is Redux?

38.   What is viewchild?

39.   What do you understand by services with reference to angular js?

40.   What are DSL Animation Functions in Angular js? List them.

41.   How Angular 4 is different from Angular 2?

42.   In how many ways the Data Binding can be done?

43.   What is Isolated Unit Tests?

44.   How to include an external css in Angular 4?

45.   What is the difference between Structural and Attribute directives?

46.   In which directory all external modules and files are stored in Angular 4

47.   What Do You Understand by Services with Reference to Angular Js?

48.   What are DSL Animation Functions in Angular js?

49.   How can you use JQuery in Angular 2/4?

50.   Is it good to use JQuery in Angular 2/4?


Recommended Free Angular Basic Course

By Angular Basics (Complete Guide – Tutorial for Beginners)


Angularjs documentation pdf Download


This article covers the basics of Angular 4 and important interview questions and answers. These questions were designed for different interviews, competitive examinations and entrance exams. We have covered questions about basic and advanced concepts that will help you improve your interview skills for Angular 4 questions.

The questions are extremely useful to all web developers, front end developers, UI / UX developers and designers. These questions will benefit all freshers, BCA, BE, BTech, MCA and college students, who want to make a career in front- end design.

Before attending an interview, master your skills by preparing frequently asked questions. This will help you to face the interview confidently.

All the best for your career in this wonderful field!!!



Leave a Reply


Jobseekh aims to become one of the best jobsites in india with Free Job Alerts for your online job search.

We provide various offering via easy Employment login, Naukri search, Free Job Alert. Its easy and Free Job Ads Posting website interface for even your first Naukri search.

Free Job Alert for your online job search



Jobseekh Inc.
Best Job Opportunities, Latest Job Openings, Career Advice, Free Jobs Alert, Online Jobs even if you are looking for Home based job, Part time jobs in India.


%d bloggers like this: