🔥type-challenges_05_ 00014 - First of Array

[hyeyoonS]

First of Array

by Anthony Fu @antfu

   

배열(튜플) T를 받아 첫 원소의 타입을 반환하는 제네릭 First<T>를 구현하세요.

예시:

type arr1 = ['a', 'b', 'c']
type arr2 = [3, 2, 1]

type head1 = First<arr1> // expected to be 'a'
type head2 = First<arr2> // expected to be 3

---

관련된 문제들

[hyeyoonS]

type First<T extends unknown[]> = T extends [] ? never : T[0]

[summerkimm]

type First<T extends any[]> = T extends [] ? never : T[0]

[drizzle96]

type First<T extends any[]> = T extends [unknown, ...any] ? T[0] : never

[hyeyoonS]

type First<T extends any[]> = T extends [infer First, ...any] ? First : never

type First<T extends unknown[]> = T extends [infer First, ...any] ? First : never

[summerkimm]

type First<T extends any[]> = T["length"] extends 0 ? never : T[0]