Web / Typescript interview questions
1. What is typescript?
TypeScript is an open-source programming language developed and maintained by Microsoft. It is a strict syntactical superset of JavaScript and adds optional static typing to the language....
2. Advantages of using typescript.
TypeScript is Object-oriented . TypeScript transpiler generates compilation error during transpiling unlike the JavaScript counterpart which is an interpreted language.
3. Who developed typescript?
Typescript developed and maintained by Microsoft .
4. Drawbacks of typescript.
Learning curve. Lack of package manager and dependency on npm.
5. Inbuilt datatypes in typescript.
Data type. Explanation....
6. What are the user-defined types in typescript?
Besides built-in data types, the user can also define his own data type using classes, interfaces, arrays, Enumerations (enum) and tuple.
7. Difference between Typescript and Javascript.
8. Does typescript support abstract class?
No, typescript supports only class and interface.
9. Does JavaScript support modules like typescript?
No, JavaScript doesn't.
10. How do I install typescript in my computer?
TypeScript can be installed and managed via npm , the Node.js package manager. To install TypeScript, make sure that the npm is installed properly using the below command....
11. How do I compile typescript files?
Typescript files has the extension .ts . Use tsc <TypeScript File Name> command to compile a typescript file via command line....
12. What are Modules in Typescript?
A module is used to organize code written in TypeScript. Modules are of 2 types, Internal Modules (aka namespaces) and External Modules also referred just as modules simply.
13. Explain interface in typescript.
Interface is a structure that defines the contract/syntax for classes to follow. Classes that are derived from an interface must follow the structure....
14. Does typescript support all object oriented paradigm?
Yes, typescript supports encapsulation, inheritance, polymorphism and abstraction.
15. How do I compile typescript files automatically with changes to file in real-time?
Using -watch or -w compiler option, we can enable auto compilation. tsc -watch typescriptFile.ts This option executes the compiler in watch mode, watch input files, and trigger recompilation on changes.
16. What is class in typescript?
The concept of class is similar to Java, Scala or any other object oriented programming language. A Class can have constructor, member variables, properties and methods.
17. What is namespace in Typescript?
A namespace is a way to logically group related classes or interfaces in a wrapper. Namespaces are simply named JavaScript objects in the global namespace....
18. What does the question mark (?) on a typescript variable/parameter name denote?
Question mark on a typescript variable marks it as optional . Any optional parameters must follow required parameters....
19. What is debouncing?
Debouncing is a programming technique that enables us to defer the execution of a potentially-complex operation rather than executing it constantly/immediately. For example, While filtering large lists based on user input, rather than filtering on every keystroke, we can use...
20. What is the difference between Subject and BehaviorSubject?
A BehaviorSubject holds one value. When it is subscribed it emits the value immediately....
21. Dynamic vs Static Typing.
In dynamically typed languages, the types are associated with run-time values and not names explicitly in your code. Dynamic examples: JavaScript, Python, Ruby, PHP....
22. What is the Difference Between '!:' and '?:' in TypeScript object definitions?
The ? marks the property optional.
