30-seconds-of-code/snippets/chunk-array.md

Chunk Array

Use Array.apply() to create a new array, that fits the number of chunks that will be produced. Use Array.map() to map each element of the new array to a chunk the length of size. If the original array can't be split evenly, the final chunk will contain the remaining elements.

const chunk = (arr, size) => 
  Array.apply(null, {length: Math.ceil(arr.length/size)}).map((v, i) => arr.slice(i*size, i*size+size));

// const myArray = [2, 2, 2, 2, 2, 2, 3, 2, 3, 2, 3, 2, 2];
// chunk(myArray, 3) -> [ [ 2, 2, 2 ], [ 2, 2, 2 ], [ 3, 2, 3 ], [ 2, 3, 2 ], [ 2 ] ]