initial (Functional Programming)

Creates a function that returns all values except the last one. Use it with pipe.

const result = pipe(array, initial());

::: info

Prefer the original es-toolkit initial in ordinary code. Use this fp variant when composing transformations with pipe.

:::

Usage

initial returns a new array without the last value of the piped array.

import { initial, pipe } from 'es-toolkit/fp';

pipe([1, 2, 3], initial()); // => [1, 2]

Parameters

This function takes no arguments; call it as initial().

Returns

((array: readonly T[]) => T[]): A function that maps a readonly T[] to all values except the last one.