TS.03.02 JuniorCore — asked often

Generics: the basics

Comes up in: Coding, Recruiter screen

This concept is being written. It gets the full five steps — explanation, predict, interview angle, practice with tests, and review cards. Here is exactly what it will cover, so you can study it elsewhere in the meantime.

What it covers

type parameters
inference from arguments
constraints with extends
default type parameters
generic interfaces and classes
keyof constraints (getProperty<T, K extends keyof T>)

Words you will know

generictype parameterconstrainttype argument

What you will practise

first<T>, pluck<T,K>, typed groupBy

Interview questions this answers

What are generics and why use them?
Type a generic debounce.