TypeScript TypeScript Type System & Generics

Question 1

What keyword is used to define a generic type parameter in TypeScript?

Accepted Answer

T (angle bracket syntax)

Answer

type

Answer

generic

Answer

var

Question 2

Which TypeScript type represents a value that can be any type and opts out of type checking?

Accepted Answer

any

Answer

unknown

Answer

never

Answer

void

Question 3

What is the difference between `unknown` and `any` in TypeScript?

Accepted Answer

`unknown` requires a type check before use; `any` does not

Answer

They are identical

Answer

`any` requires a type check before use; `unknown` does not

Answer

`unknown` only works with primitives

Question 4

Which utility type makes all properties of a type optional?

Accepted Answer

Partial<T>

Answer

Required<T>

Answer

Readonly<T>

Answer

Pick<T, K>

Question 5

What does the `never` type represent in TypeScript?

Accepted Answer

A type with no possible values, such as the return of a function that always throws

Answer

A value that is undefined

Answer

A value that is null

Answer

An optional parameter

Question 6

Which of the following correctly applies a generic constraint in TypeScript?

Accepted Answer

function fn<T extends object>(x: T)

Answer

function fn<T>(x: T) where T extends object

Answer

function fn<T: object>(x: T)

Answer

function fn<T implements object>(x: T)