Breakup an array into an array of arrays of a given size

chunk.js

function chunk(arr, size) {
  var final = [];
  for (i = 0; i < Math.ceil(arr.length/size); i++) {
    final.push(arr.slice(i*size, (i+1)*size));
  }
  return final;
}
chunk(["a", "b", "c", "d", "e"], 2); // returns [["a", "b"], ["c", "d"], ["e"]]