Chunk array

chunk.js

function chunk(array, size) {
    const chunked_arr = [];
    for (let i = 0; i < array.length; i++) {
      const last = chunked_arr[chunked_arr.length - 1];
      if (!last || last.length === size) {
        chunked_arr.push([array[i]]);
      } else {
        last.push(array[i]);
      }
    }
    return chunked_arr;
}