15/Sep/2021 | 10 minutes to read
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Here is a List of essential TypeScript Interview Questions and Answers for Freshers and mid level of Experienced Professionals. All answers for these TypeScript questions are explained in a simple and easiest way. These basic, advanced and latest TypeScript questions will help you to clear your next Job interview.
These questions are targeted for front end developers who use TypeScript with Angular, React etc. You must know the answers of these frequently asked TypeScript interview questions to clear an interview.
1. What is TypeScript?
TypeScript is an open-source programming language. It's developed and maintained by Microsoft. TypeScript is built over JavaScript means - it's a superset of JavaScript. TypeScript provides the capability for type-checking and offers class, object and interface components to write powerful code. All JavaScript code is also TypeScript code without type-checking. All TypeScript code is compiled into JavaScript code by TypeScript compiler or Babel. For more about TypeScript visit - TypeScript.
2. Explain different types in TypeScript.
TypeScript offers three primitive types similar to JavaScript: string, number and boolean. Apart from these primitive types, TypeScript provides the below types.
3. Explain Type assertions in TypeScript.
Type Assertion can be defined as type casting in other programming languages such as C#, Java etc but It does not perform any
restructuring or additional checks on data. It tells the compiler to believe that the Programmer knows what he is doing. It does not have any run-time impact
and TypeSCript compiler assumes that you have performed required specific checks.
You create type assertions using two syntax as below.
As syntax -
let myValue: unknown = "some string value";
let valueLength: number = (myValue as string).length;
let myValue: unknown = "some string value";
let valueLength: number = (<string>myValue).length;
4. What object-oriented features TypeScript supports?
TypeScript supports various object-oriented features similar to other programming languages. It provides good support for Inheritance, Interface, Class, Object, Methods, Getters/Setters, Generics, Abstracts and many more. For more about class level object-oriented features visit Object-Oriented Classes.
5. Explain generics in TypeScript.
6. How to use 'as' in TypeScript?
7. What is the compilation context in TypeScript?
8. How to check null and undefined?
9. What are const and readonly modifiers?
10. Explain getter and setter.
11. What is the use of map files in TypeScript?
12. What access modifiers TypeScript supports?
13. Explain contextual typing in TypeScript.
14. How to import modules? Explain relative and non-relative module imports.
15. Explain different components of TypeScript.
16. How to extend an interface from a class?
17. What are the property decorators?
18. How to access a class outside of that module?
19. Does TypeScript support function overloading? If yes then explain the overloading?
20. What is the use of the Triple-Slash Directive? Give some examples.
21. Explain TypeScript Definition Manager?
22. What is JSX? Does TypeScript support it?
23. What is statically typed and dynamically typed language?
24. Explain interface and type statements?
25. Explain TypeScript Ambients.
26. Why to use the declare keyword in TypeScript?
27. How does TypeScript compilation work?
1. How much will you rate yourself in TypeScript?
When you attend an interview, Interviewer may ask you to rate yourself in a specific Technology like TypeScript, So It's depend on your knowledge and work experience in TypeScript.
2. What challenges did you face while working on TypeScript?
This question may be specific to your technology and completely depends on your past work experience. So you need to just explain the challenges you faced related to TypeScript in your Project.
3. What was your role in the last Project related to TypeScript?
It's based on your role and responsibilities assigned to you and what functionality you implemented using TypeScript in your project. This question is generally asked in every interview.
4. How much experience do you have in TypeScript?
Here you can tell about your overall work experience on TypeScript.
5. Have you done any TypeScript Certification or Training?
It depends on the candidate whether you have done any TypeScript training or certification. Certifications or training are not essential but good to have.
We have covered some frequently asked TypeScript Interview Questions and Answers to help you for your Interview. All these Essential TypeScript Interview Questions are targeted for mid level of experienced Professionals and freshers.
While attending any TypeScript Interview if you face any difficulty to answer any question please write to us at info@qfles.com. Our IT Expert team will find the best answer and will update on the portal. In case we find any new TypeScript questions, we will update the same here.