toFilled (Functional Programming)

Creates a function that returns a filled copy of an array. Use it with pipe.

const result = pipe(array, toFilled(value, start, end));

::: info

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

:::

Usage

toFilled fills a copy of the piped array with value from start up to, but not including, end. It follows Array.prototype.fill index semantics and does not mutate the input array.

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

const array = [1, 2, 3, 4];

pipe(array, toFilled(0, 1, 3)); // => [1, 0, 0, 4]
array; // => [1, 2, 3, 4]

Parameters

• value (U): The value to write into the returned array.
• start (number, optional): The start index. Defaults to 0.
• end (number, optional): The end index. Defaults to the array length.

Returns

((array: readonly T[]) => Array<T | U>): A function that maps a readonly T[] to a filled copy.