Run results for: for vs for (reverse) vs forEach vs every

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.45 Safari/537.36

Browser: Chrome 96

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
for	5.7 Ops/sec
for (with length)	13.6 Ops/sec
for (reverse)	14.0 Ops/sec
for (reverse with length)	13.2 Ops/sec
forEach	9.9 Ops/sec

Script Preparation code:

function generateTestArray() {
	var result = [];

	for (let i = 0; i < 1000; ++i) {
		result.push({
			a: i,
			b: i / 2,
			r: 0,
		});
	}

	return result;
}

var array = generateTestArray();

Tests:

for
for (var i = 0; i < array.length; i++) { let r = array[i]; }
for (with length)
var length = array.length; for (var i = 0; i < length; i++) { let r = array[i]; }
for (reverse)
for (var i = array.length; --i >= 0;) { let r = array[i]; }
for (reverse with length)
var length = array.length; for (var i = length; --i >= 0;) { let r = array[i]; }
forEach
array.forEach(function(i) { let r = array[i]; });
every
array.every(function(i) { let r = array[i]; return true; });

Run results for: for vs for (reverse) vs forEach vs every

for

for (with length)

for (reverse)

for (reverse with length)

forEach

every