Split an array into sized chunks

split-array-into-chunks.js

/**
 * Takes an array and splits it into sized chunks
 * that are <= the passed chunkSize param
 *
 * @param {Array} source Source array
 * @param {Number} chunkSize The max size of each chunk
 * @returns {Array} A 2d array of chunks
 */
const splitArrayIntoChunks = (source, chunkSize) => {
  if (!source.length) {
    return [];
  }

  if (source.length <= chunkSize) {
    return [source];
  }

  return [source.slice(0, chunkSize)].concat(splitArrayIntoChunks(source.slice(chunkSize), chunkSize));
};

module.exports = splitArrayIntoChunks;

Example usage

const source = ['hello', 'I', 'am', 'an', 'array', '🙂'];
const chunks = splitArrayIntoChunks(source, 2);

// Result 
[['hello', 'I'], ['am', 'an'], ['array', '🙂']]