Skip to solution
mediumFrontend

What do Exclude, Extract, and NonNullable do?

608 views
01

Understand the problem

Explain union utility types.

excludeextract
02

Attempt it yourself

Sketch your approach before reading the solution — that's what interviews test.

Nudge consolestandby

Stuck? Beam a request up — the console returns a conceptual nudge that guides your logic without spoiling the implementation.

03

Study the solution

Exclude<T, U> removes from union T the members assignable to U; Extract<T, U> keeps only those; NonNullable<T> removes null and undefined. They're conditional-type helpers for manipulating union members.

Solution ready — 2 min read

Classified // press E to declassify

04

Join the discussion

Discussion (0)

Sign in to join the discussion.

No responses yet. Be the first to share what you think.

Transmission complete // awaiting log

KEEP THE
STREAK ALIVE.

Dossier 29 of 70 decoded in the TypeScript track. One more won't hurt.

Back to track