Run results for: Chunking array

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.102 Safari/537.36

Browser: Chrome 85

Operating system: Windows 7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Using reduce	239880.6 Ops/sec
Using while	1087865.0 Ops/sec
Using reduce 2 and push	2002305.0 Ops/sec
Using for loop and push	2096509.0 Ops/sec

Script Preparation code:


function chunkReduce(array, size = 1) {
  return array.reduce((target, item, index) => {
    if (index % size === 0) {
      return [...target, [item]]
    }
    const last = target[target.length - 1]
    return [...target.slice(0, target.length - 1), [...last, item]]
  }, [])
}
function chunkReduce2(array, size = 1) {
  let key = -1
  return array.reduce((target, item, index) => {
    if (index % size === 0) {
      key++
      target[key] = []
    }
    target[key].push(item)
	return target
  }, [])
}
function chunkReduce3(array, size = 1) {
  let key = -1
  const length = array.length
  const target = []
  for (let index = 0; index < length; ++index) {
    const item = array[index]
    if (index % size === 0) {
      key++
      target[key] = []
    }
    target[key].push(item)
  }
  return target
}


function chunkWhile(array, size = 1) {
  var length = array == null ? 0 : array.length;
  if (!length || size < 1) {
    return [];
  }
  var index = 0,
      resIndex = 0,
      result = Array(Math.ceil(length / size));

  while (index < length) {
    result[resIndex++] = array.slice(index, (index += size));
  }
  return result;
}

Tests:

Using reduce
chunkReduce([1,2,3,4,5,6,7,8,9,1,0,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,7,14,6,4,56,4,5], 4)
Using while
chunkWhile([1,2,3,4,5,6,7,8,9,1,0,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,7,14,6,4,56,4,5], 4)
Using reduce 2 and push
chunkReduce2([1,2,3,4,5,6,7,8,9,1,0,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,7,14,6,4,56,4,5], 4)
Using for loop and push
chunkReduce3([1,2,3,4,5,6,7,8,9,1,0,2,3,4,5,6,7,8,9,10,1,2,3,4,5,6,7,8,9,7,14,6,4,56,4,5], 4)

Run results for: Chunking array

Using reduce

Using while

Using reduce 2 and push

Using for loop and push