Head

Since 1.0.0

Get the first element of a tuple.

Signature

type Head<T extends readonly unknown[]> = T extends readonly [infer H, ...unknown[]]
  ? H
  : T extends readonly (infer E)[]
    ? E
    : never

Parameters

Parameter	Description
T	The tuple type

Examples

Basic Usage

import type { Head } from 'uni-types'

type First = Head<[1, 2, 3]> // 1
type FirstStr = Head<['a', 'b', 'c']> // 'a'

Single Element

type Single = Head<[string]> // string

With Arrays

type FromArray = Head<string[]> // string
type FromNumberArray = Head<number[]> // number

Empty Tuple

type Empty = Head<[]> // never

Related

• Last - Get last element
• Tail - Get all elements except first
• Init - Get all elements except last