partition (Functional Programming)

Creates a function that splits values into passing and failing groups. Use it with pipe.

const result = pipe(array, partition(predicate));

::: info

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

:::

Usage

partition returns a pair of arrays. The first array contains values for which predicate returns true, and the second contains the rest.

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

pipe(
  [1, 2, 3, 4],
  partition(value => value % 2 === 0)
); // => [[2, 4], [1, 3]]

Parameters

• predicate ((value: T) => boolean): The function that decides which group each value belongs to.

Returns

((array: readonly T[]) => [truthy: T[], falsy: T[]]): A function that maps a readonly T[] to passing and failing arrays.