TS.06.01 JuniorCore — asked often

Built-in utility types

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

Partial, Required, Readonly, Pick, Omit, Record, Exclude, Extract, NonNullable, ReturnType, Parameters, ConstructorParameters, InstanceType, Awaited, NoInfer
Omit is not distributive over unions

Words you will know

utility type

What you will practise

use each in a realistic API type

Interview questions this answers

Implement Pick and Omit.
What is the difference between Exclude and Omit?
Why does Omit behave badly on union types? How do you fix it?
Implement Awaited.