Benchmark: How to reduce an object to a sub-object fast

Script Preparation code:

var source = {
  a: 0,
  b: 1,
  c: 2,
  d: 3,
  e: 4,
  f: 5,
  various: null
}

var select = ['a', 'b', 'c', 'd', 'e', 'f']

var selectReduceAssign = () =>
  select.reduce(
    (accumulator, current) =>
      Object.assign(accumulator, { [current]: source[current] }),
    {}
  )

var selectReduceSpread = () =>
  select.reduce(
    (accumulator, current) =>
      ({ ...accumulator, [current]: source[current] }),
    {}
  )

var selectReduceAddExplicitly = () =>
  select.reduce(
    (accumulator, current) =>
    {
      accumulator[current] = source[current]
      return accumulator
    },
    {}
  )

var selectPick = ({ a, b, c, d, e, f }) => ({ a, b, c, d, e, f })

Tests:

selectReduceAssign
selectReduceAssign()
selectReduceSpread
selectReduceSpread()
selectReduceAddExplicitly
selectReduceAddExplicitly()
selectPick
selectPick(source)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
selectReduceAssign
selectReduceSpread
selectReduceAddExplicitly
selectPick

Fastest: N/A

Slowest: N/A

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Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/116.0

Browser/OS: Firefox 116 on Windows

View result in a separate tab

Test name	Executions per second
selectReduceAssign	2213031.0 Ops/sec
selectReduceSpread	1871662.0 Ops/sec
selectReduceAddExplicitly	6851320.0 Ops/sec
selectPick	98379580.0 Ops/sec

How to reduce an object to a sub-object fast (version: 0)

Comparing performance of: selectReduceAssign vs selectReduceSpread vs selectReduceAddExplicitly vs selectPick

Created: 9 months ago by: Registered User

Jump to the latest result

selectReduceAssign

selectReduceSpread

selectReduceAddExplicitly

selectPick

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A