#10Medium

Tuple to Union

Implement a generic `TupleToUnion<T>` which covers the values of a tuple to its values union. Learn conditional types with `infer`, union type manipulation, tuple manipulation in this medium-level challenge on TypeScriptPro.

In this medium-level challenge, you'll implement a generic TupleToUnion<T> which converts the values of a tuple to a union.

Challenge Instructions: Tuple to Union

Medium

Implement a generic TupleToUnion<T> which covers the values of a tuple to its values union.

For example

type Arr = ['1', '2', '3']
 
type Test = TupleToUnion<Arr> // expected to be '1' | '2' | '3'

Change the following code to make the test cases pass (no type check errors).

Loading...

Video Walkthrough

Detailed Explanation

To convert a tuple to a union, we use indexed access:

type TupleToUnion<T extends unknown[]> = T[number]

How it works:

T[number] accesses all numeric indices of the tuple - this produces a union of all tuple element types.

This challenge is originally from here.

Share this challenge

Join early, learn faster.

Be the first to access the course, unlock exclusive launch bonuses, and get special early-bird pricing before anyone else.

No spam, unsubscribe at any time. We respect your privacy.

Limited Availability

Only 27 Spots left

Early Access

Get 1 month early access

>75% Off

Pre-Launch discount