Run results for: toISOString and literalISO 2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36

Browser: Chrome 108

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
toISOString	1869.1 Ops/sec
concat	5006.6 Ops/sec
toISOStringLiteral	5307.1 Ops/sec

Script Preparation code:

var date = new Date();

function toISOString(date) {
	return date.toISOString();
}

function toISOStringLiteral(date) {
 

  const d = date.getUTCDate();
  const m = date.getUTCMonth() + 1;
  const y = date.getUTCFullYear();
  const hh = date.getUTCHours();
  const mm = date.getUTCMinutes();
  const ss = date.getUTCSeconds();
  const mss = date.getUTCMilliseconds();

  const ds = d <= 9 ? `0${d}` : `${d}`;
  const ms = m <= 9 ? `0${m}` : `${m}`;

  const hhs = hh <= 9 ? `0${hh}` : `${hh}`;
  const mms = mm <= 9 ? `0${mm}` : `${mm}`;
  const sss = ss <= 9 ? `0${ss}` : `${ss}`;
  let msss = mss <= 9 ? `0${mss}` : `${mss}`;
  msss = mss <= 99 ? `0${msss}` : msss;

  return `${y}-${ms}-${ds}T${hhs}:${mms}:${sss}.${msss}Z`;
};

function concat(date) {
 	var d = date.getUTCDate();
	var m = date.getUTCMonth() + 1;
	var y = date.getUTCFullYear();
  	var hh = date.getUTCHours();
 	var mm = date.getUTCMinutes();
  	var ss = date.getUTCSeconds();
  	var ms = date.getUTCMilliseconds();
  	var day = d <= 9 ? '0' + d : '' + d;
    var month = m <= 9 ? '0' + m : '' + m;
    var year = '' + y;
  
  	hh = hh <= 9 ? '0' + hh : '' + hh;
    mm = mm <= 9 ? '0' + mm : '' + mm;
    ss = ss <= 9 ? '0' + ss : '' + ss;
    ms = ms <= 9 ? '0' + ms : '' + ms;
    ms = ms <= 99 ? '0' + ms : '' + ms;
  
	return year + '-' + month + '-' + day + 'T' + hh + ':' + mm + ':' + ss + '.' + ms + 'Z';
}

Tests:

toISOString
for (var i=0; i<1000; ++i) { toISOString(date); }
concat
for (var i=0; i<1000; ++i) { concat(date); }
toISOStringLiteral
for (var i=0; i<1000; ++i) { toISOStringLiteral(date); }