at (Functional Programming)

Creates a function that returns the values at the given indices. Use it with pipe.

const result = pipe(array, at(indices));

::: info

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

:::

Usage

at reads values from the piped array at each index in indices. Negative indices count from the end, matching Array.prototype.at.

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

pipe(['a', 'b', 'c'], at([0, -1])); // => ['a', 'c']

Parameters

• indices (number[]): The indices to read from the piped array.

Returns

((array: readonly T[]) => T[]): A function that maps a readonly T[] to the selected values.