Kōdo no musō-ka Kōdo no musō-ka - 22 days ago 5
Javascript Question

Splitting an array up into chunks of a given size

I have written a function which takes two parameters: (1) an Array, (2) size of the chunk.

function chunkArrayInGroups(arr, size) {

var myArray = [];

for(var i = 0; i < arr.length; i += size) {
myArray.push(arr.slice(i,size));
}

return myArray;
}


I want to split this array up into chunks of the given size.

chunkArrayInGroups(["a", "b", "c", "d"], 2)


should return:
[["a", "b"], ["c", "d"]]
.

I get back:
[["a", "b"], []]

Answer

You misunderstood what the slice parameters mean. The second one is the index until which (not included) you want to get the subarray. It's not a length.

array.slice(from, to); // not array.slice(from, length)

function chunkArrayInGroups(arr, size) {
  var myArray = [];
  for(var i = 0; i < arr.length; i += size) {
    myArray.push(arr.slice(i, i+size));
  }
  return myArray;
}
console.log(chunkArrayInGroups(["a", "b", "c", "d"], 2));