FindIndex

Since 1.4.0

Finds the index of the first element in a tuple that matches a given predicate type. Returns -1 if no match is found.

Signature

export type FindIndex<T extends unknown[], P, Acc extends 0[] = []> = T extends [
	infer First,
	...infer Rest,
]
	? First extends P ? Acc['length'] : FindIndex<Rest, P, [...Acc, 0]>
	: -1

Parameters

Parameter	Description
T	The tuple to search through
P	The predicate type to match against
Acc	Internal accumulator for tracking index (default: [])

Examples

Basic Usage

import type { FindIndex } from 'uni-types'

type Index = FindIndex<[1, 'a', 2, 'b'], string> // 1

No Match Found

import type { FindIndex } from 'uni-types'

type Index = FindIndex<[1, 2, 3], string> // -1

Related

• Find - Find first matching element
• IndexOf - Get index of specific element
• Includes - Check if tuple includes element