Top 60 Angular interview questions to help organizations hire expert programmers

Angular is an open JavaScript framework used to create single-page applications in TypeScript, which Google supports. Initially, Angular was supposed to be launched as the second version of the Angular.js framework, but with some design decisions, the framework was launched as a completely separate entity. Today, Angular is one of the most popular frameworks used across industries, with JavaScript being the most commonly used client-side language.

In order to hire top developers with Angular skills, applicants should first be screened using relevant assessment tests and then evaluated using structured Angular interview questions to test their technical and soft skills.

Angular developers are front-end developers responsible for creating and managing dynamic web applications, building components, ensuring data consistency, integrating backend APIs, performance optimization, etc. These developers need to have a robust understanding of Angular’s module-based architecture to translate designs and wireframes into quality code while optimizing applications for various platforms. They should also be able to collaborate effectively with backend developers and UI/UX designers and conduct testing and debugging to enhance user experience

1. What is Angular?
2. What is TypeScript?
3. What are single-page applications?
4. What skills are required to use Angular?
5. What soft skills are important for Angular developers?
6. What is data binding?
7. What kind of data binding is employed by Angular developers?
8. What is the difference in Angular.js and Angular?
9. What are decorators in Angular?
10. What are the advantages of using Angular?
11. What are templates in Angular?
12. What are annotations?
13. What are directives?
14. What are AOT compilations?
15. Why are AOT compilations used?
16. What is a component in Angular?
17. What are pipes in Angular?
18. What is the PipeTransform interface?
19. What are Pure Pipes?
20. What are Impure Pipes?
21. What is the ngModule?
22. What are Angular filters?
23. What is the date filter in Angular?
24. What is the inbuilt Json filter in Angular?
25. What is the limitTo filter in Angular?
26. What are lowercase Angular filters?
27. What is view encapsulation in Angular?
28. What are Angular controllers?
29. What is the meaning of scope?
30. What are lifecycle hooks?
31. What is String Interpolation?
32. What is a Template statement?
33. Are there any disadvantages to using Angular?
34. What is a DOM?
35. What is the difference between Angular and jQuery?

1. What skills are required to use Angular?

This is one of the most essential Angular developer interview questions. Other than Angular, important skills are HTML, CSS, TypeScript, Angular Command Line Interface, and JavaScript. Angular developers should also be able to demonstrate that they have the necessary skills to become a valuable addition to the organization.

2. What soft skills are important for Angular developers?

Candidates should know that technical skills are only one of the requirements for becoming a good Angular developer. Skilled Angular developers should possess crucial soft skills, including empathy, communication, time management, and attention to detail. It is also vital for Angular developers to work well in teams.

3. What are the advantages of using Angular?

Such Angular developer interview questions are designed to assess if candidates understand beyond theoretical knowledge. They should know that the main strength of Angular is that it enables developers to write clean, easy-maintenance code. They should cover that Angular provides reusable components, data binding, and modules for easy application creation.

4. What is the difference in Angular.js and Angular?

Candidates should explain that Angular uses TypeScript, Angular.js uses JavaScript, and Angular.js supports a model-view-controller design, while Angular uses different directives and components. Additionally, Angular can also support mobile browsers, which Angular.js cannot.

5. What are Angular filters?

Candidates should be able to demonstrate their knowledge of Angular filters, which developers use to filter items from several items of an array or object array. They should also know that a filter will select the subset of the items that it takes from the array, returning a new array to display the item on the user interface.

1. What is a JIT compilation?
2. What is the difference between JIT compilations and AOT compilations?
3. What does the @Component decorator do?
4. What are services used for in Angular?
5. What are promises in Angular?
6. What are observables in Angular?
7. What is the reactive-form method?
8. What is bootstrap?
9. What is eager loading?
10. What is lazy loading?
11. What is RxJS?
12. How to create components dynamically?

1. What is a JIT compilation?

JIT compilations are also known as dynamic compilations. Candidates with experience in Angular should know that JIT stands for just-in-time and that a JIT compilation refers to a process used by developers to compile code during program execution rather than before.

2. What is the difference between JIT compilations and AOT compilations?

AOT stands for ahead-of-time, while JIT stands for just-in-time. The code is already compiled during the application’s building process in AOT compilations. On the other hand, in JIT compilations, the compiler is downloaded, and the code is compiled right before displaying the output in the browser. Candidates should be aware that AOT loading is faster than JIT as the compilation in JIT happens straight at runtime.

3. What are services used for in Angular?

Candidates should be able to explain that developers use Angular services to complete tasks that multiple components use. Services are also used to complete operational tasks, ensuring the developer does not have to rewrite code. Candidates should be able to give examples of tasks that can be completed using Angular services, like database management and image fetching.

4. What are promises in Angular?

Angular developer candidates should know that promises are used to handle asynchronous events and to emit single values at a time. Promises differ from observables, which are used to handle multiple asynchronous events over a certain period. Candidates should also be aware that promises are executed straightaway after creation.

5. What is the reactive-form method?

The reactive-form method centers around data flows, and using reactive forms involves using components to manage data flow directly. Candidates should know that the reactive-form method differs from the template-form method, as reactive forms work with code.

1. What does the ngOnChanges() lifecycle hook do?
2. What does the ngOnInit() lifecycle hook do?
3. What does the ngDoCheck() lifecycle hook do?
4. What does the ngAfterContentInit() lifecycle hook do?
5. What does the ngAfterContentChecked() lifecycle hook do?
6. What does the ngAfterViewChecked() lifecycle hook do?
7. What does the ngOnDestroy() lifecycle hook do?
8. How is the ngFor directive used in a tag?
9. What does manual bootstrapping do?
10. What does automatic bootstrapping do?
11. Give the names of three Angular building blocks and explain why they are used.
12. What is the digest cycle process in Angular?
13. How to create a service in Angular?

1. How is the ngFor directive used in a tag?

The ngFor directive is used in Angular to create tables and lists on HTML templates. Developers use the directive to iterate over objects and make templates.

2. What does manual bootstrapping do?

Manual bootstrapping is used by developers to initialize an app, giving them more control over the process. Candidates should be able to explain how using this method provides developers extra flexibility for completing other operations before the page compilation process.

3. Give the names of three Angular building blocks and explain why they are used.

Candidates may respond to such Angular coding interview questions with any important building blocks. Some of the most important Angular building blocks they may include in their answers are dependency injection, services, and components. Developers use dependency injection to provide the required dependencies to new components. Services have several properties, like values, functions, and features, which contribute to successful Angular application building. Components can be used to control different views or parts of the screen. Components also feature the application logic defined by developers in a class.

4. What is the digest cycle process in Angular?

Candidates should be able to explain that the digest cycle process is where developers monitor watchlists to track changes happening to a watch variable. They should be able to demonstrate that developers can also compare each version of the model values using each digest cycle.

5. How to create a service in Angular?

There are several ways to create services in Angular, and applicants may have different approaches. Developers can specify the provideIn property using the @Injectible decorator. They can also register the article service at the root level and specify it in the code. This means Angular will create a single service-class instance that any class can use. Another thing that candidates may explain in their answer is that if the service class’s scope is to be reduced, developers can register it within the @Component decorator in the provider’s property.

1. Conduct complete skills assessments for candidates

It is crucial to start the recruitment process after sourcing applicants by administering comprehensive skills assessment tests to screen candidates based on their skills, aptitude, etc., before shortlisting candidates for the interview rounds.

2. Discuss the details of the job role in question

It is a good idea to start each interview by providing candidates with detailed information about the role. Build on the original job description shared and inform them about the role. Add details about the company’s structure and their role if they are hired. This will help candidates gain a better understanding of the work environment.

3. Tailor the Angular interview questions according to the candidate’s experience

The Angular coding and interview questions should be chosen with care. Consider each candidate’s experience in Angular and tailor the questions accordingly. For example, using advanced Angular interview questions and answers for assessing junior developers and using basic Angular developer interview questions to assess senior developers will impact the candidate experience negatively.

The Angular interview questions should align with the candidate’s seniority, which will help evaluate their knowledge and skills accurately and show candidates that the company values their time, skills, and experience.

4. Take notes

No one can remember every little detail from an interview. Additionally, recruitment is a collaborative process based on the input and data collected from all stakeholders involved. Therefore, it is important to take detailed notes. Note-taking also enables reviewing all candidates’ responses once interviews have been completed to make the right hiring decision.

5. Provide feedback to candidates who are not selected

It is good practice to improve the candidate experience by letting candidates know that their application is not being retained and providing them with feedback based on the results of the tests and the interview.

Mercer | Mettl offers a comprehensive online assessment suite that can be used by organizations to objectively screen Angular developers based on the needs of the organization. Mercer | Mettl also provides a range of Angular developer skills assessments with various difficulty levels to help organizations streamline their recruiting practices.

Other tools offered by Mercer | Mettl for tech hiring include tech screening tools, online code interview tools, Mercer | Mettl I/O, Mercer | Mettl Codelysis, a virtual hackathon platform, and more.

The Angular developer is a key position most tech companies hire for. Angular developer interview questions can be a comprehensive tool for employers and candidates, helping match the right talent with the right job roles. Review and evaluate the above list of questions and identify the best fit of questions for a specific job role.