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Library/JavaScript/Array Chunk
javascriptbeginnerarraysutilities

How to implement Array Chunk in Javascript

Split an array into chunks of a specified size

Quick Answer

The array chunk function divides a large array into smaller sub-arrays of a given size. It is the foundation for pagination, batch API requests, and grid-based UI rendering.

Code Snippet

1function chunk(array, size) {
2  const chunks = [];
3  for (let i = 0; i < array.length; i += size) {
4    chunks.push(array.slice(i, i + size));
5  }
6  return chunks;
7}

What is Array Chunk?

The array chunk function divides a large array into smaller arrays of a specified size. This is useful when you need to process data in batches, implement pagination, or organise data into groups for display purposes.

How It Works

  1. 1A results array is initialised to hold the chunks.
  2. 2A for loop steps through the source array by the chunk size.
  3. 3Array.slice extracts each chunk from the current index to index + size.
  4. 4Each chunk is pushed into the results array.
  5. 5The completed array of chunks is returned.

Common Use Cases

  • Pagination — split large datasets into pages
  • Batch processing — process items in manageable groups
  • Grid layouts — organise items into rows and columns
  • API requests — send data in smaller batches

Key Benefits

  • Simple and efficient array manipulation
  • Reduces memory overhead for large datasets
  • Improves performance with batch processing
  • Essential for pagination implementation

Common Mistakes to Avoid

  • Passing a size of 0 or a negative number — add a guard clause to throw or return early.
  • Mutating the original array — Array.slice does not mutate, so this implementation is safe.
  • Not accounting for uneven arrays — the last chunk will simply be smaller than the requested size.

Quick Tips

  • Click the "Copy" button above to copy the code to your clipboard
  • This code is production-ready and can be used in your projects immediately
  • Check out related snippets below for more javascript examples

Frequently Asked Questions

Does array chunk mutate the original array?

No. Array.slice returns a new array and does not modify the original.

How do I chunk an array in one line?

You can use Array.from({ length: Math.ceil(arr.length / size) }, (_, i) => arr.slice(i * size, i * size + size)).

Is there a lodash equivalent?

Yes. _.chunk(array, size) from lodash does the same thing.

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About This Javascript Code Snippet

This free javascript code snippet for array chunk is production-ready and copy-paste friendly. Whether you are building a web app, API, or frontend interface, this beginner-level example will help you implement array chunk quickly and correctly.

All snippets in the Snippetly library follow javascript best practices and are tested for real-world use. You can adapt this code to work with React, Vue, Node.js, or any project that uses javascript.

Tags: arrays, utilities  | Language: javascript  | Difficulty: beginner  | Category: JavaScript

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