Run results for: for vs foreach vs some

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_6_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.6.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 15

Operating system: iOS 15.6.1

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
for..in	177455.3 Ops/sec
foreach	6762039.5 Ops/sec
some	11928238.0 Ops/sec
for	145073.6 Ops/sec
for with predefined size	287344.2 Ops/sec
while	4371932.5 Ops/sec
every	24564618.0 Ops/sec

Script Preparation code:

var array = new Array(100);
for(var i = 0; i < array.length; i++) {
	array[i] = Math.random();
}

Tests:

for..in
for (var i in array) { array[i]; }
foreach
array.forEach(function(item, index) { return item; });
some
array.some(function(item, index) { return item === array[index]; });
for
for (var i = 0; i < array.length; i++) { array[i]; }
for with predefined size
var size = array.length for (var i = 0; i < size; i++) { array[i]; }
while
while((a=array.pop()) !== undefined){ //do your stuff }
every
array.every(function(item, index) { return item === array[index]; });

Run results for: for vs foreach vs some

Compare loop performance

for..in

foreach

some

for

for with predefined size

while

every