es-toolkit/docs/reference/array/chunk.md

chunk

Splits an array into smaller arrays of a specified length.

This function takes an input array and divides it into multiple smaller arrays, each of a specified length. If the input array cannot be evenly divided, the final sub-array will contain the remaining elements.

Signature

function chunk<T>(arr: T[], size: number): T[][];

Parameters

• arr (T[]): The array to be chunked into smaller arrays.
• size (number): The size of each smaller array. Must be a positive integer.

Returns

(T[][]) A two-dimensional array where each sub-array has a maximum length of size.

Throws

Throws an error if size is not a positive integer.

Examples

import { chunk } from 'es-toolkit/array';

// Splits an array of numbers into sub-arrays of length 2
chunk([1, 2, 3, 4, 5], 2);
// Returns: [[1, 2], [3, 4], [5]]

// Splits an array of strings into sub-arrays of length 3
chunk(['a', 'b', 'c', 'd', 'e', 'f', 'g'], 3);
// Returns: [['a', 'b', 'c'], ['d', 'e', 'f'], ['g']]

Demo

::: sandpack

import { chunk } from 'es-toolkit/array';

console.log(chunk([1, 2, 3, 4, 5], 2));

:::

Lodash Compatibility

Import chunk from es-toolkit/compat for full compatibility with lodash.

• chunk does not throw when size less than one is given.
• chunk accepts fractional values, which are rounded down to the nearest integer.

import { chunk } from 'es-toolkit/compat';

chunk([1, 2, 3], 0); // Returns []

Performance Comparison

	Bundle Size	Performance
es-toolkit	238 bytes (92.4% smaller)	9,338,821 times (11% slower)
es-toolkit/compat	307 bytes (90.2% smaller)	9,892,157 times (5% slower)
lodash-es	3,153 bytes	10,523,270 times