Run results for: Intl.NumberFormat vs toLocalString vs string split vs toFixed vs bignumber vs regex

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.113 Safari/537.36

Browser: Chrome 94

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
toLocaleString	23925.5 Ops/sec
Intl.NumberFormat	22550.8 Ops/sec
string split & reduce	829920.6 Ops/sec
toFixed	3213086.2 Ops/sec
bignumber	297915.6 Ops/sec
numberWithCommas	928390.2 Ops/sec

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/bignumber.js/9.0.1/bignumber.min.js"></script>

Script Preparation code:

function pricize (num, decimal = 0) {
  const intPart = Math.floor(num)
  const intPieces = intPart.toString().split('')
  const len = intPieces.length
  const intStr = intPieces.reduce((result, chr, index, array) => {
    const pos = len - index
    result += (index !== 0 && pos % 3 === 0) ? ',' + chr : chr
    return result
  }, '')

  const decStr = decimal > 0
    ? num.toFixed(decimal + 1).toString().slice(-(decimal + 2), -1) // toFixed() は四捨五入してしまうので(decimal + 1)桁まで求めて切り取る
    : ''

  return intStr + decStr
}

function numberWithCommas(x) {
    return x.replace(/\B(?<!\.\d*)(?=(\d{3})+(?!\d))/g, ",");
}

var target = 123456789.123456789
var options = {minimumFractionDigits: 3, maximumFractionDigits: 3}

Tests:

toLocaleString
var a = target.toLocaleString('en-US', options);
Intl.NumberFormat
var a = new Intl.NumberFormat('en-US', options).format(target)
string split & reduce
var a = pricize(target, 3)
toFixed
var a = target.toFixed(3)
bignumber
var a = new BigNumber(target).toFormat(3)
numberWithCommas
var a = numberWithCommas(target.toFixed(3))

Run results for: Intl.NumberFormat vs toLocalString vs string split vs toFixed vs bignumber vs regex

toLocaleString

Intl.NumberFormat

string split & reduce

toFixed

bignumber

numberWithCommas