Skip to main content
Using Deno in production at your company? Earn free Deno merch.
Give us feedback
Module

std/collections/chunk.ts

The Deno Standard Library
Go to Latest
File
// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Splits the given array into chunks of the given size and returns them. * * @example * ```ts * import { chunk } from "https://deno.land/std@$STD_VERSION/collections/chunk.ts"; * import { assertEquals } from "https://deno.land/std@$STD_VERSION/assert/assert_equals.ts"; * * const words = [ * "lorem", * "ipsum", * "dolor", * "sit", * "amet", * "consetetur", * "sadipscing", * ]; * const chunks = chunk(words, 3); * * assertEquals( * chunks, * [ * ["lorem", "ipsum", "dolor"], * ["sit", "amet", "consetetur"], * ["sadipscing"], * ], * ); * ``` */export function chunk<T>(array: readonly T[], size: number): T[][] { if (size <= 0 || !Number.isInteger(size)) { throw new Error( `Expected size to be an integer greater than 0 but found ${size}`, ); }
if (array.length === 0) { return []; }
const ret = Array.from<T[]>({ length: Math.ceil(array.length / size) }); let readIndex = 0; let writeIndex = 0;
while (readIndex < array.length) { ret[writeIndex] = array.slice(readIndex, readIndex + size);
writeIndex += 1; readIndex += size; }
return ret;}