Run results for: Array forEach callback function as a parameter vs as a predefined variable + compared to using callback parameters vs without + for..of, for..in, for loop

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Linux

Device Platform: Desktop

Date tested: 24 days ago

Test name	Executions per second
Array forEach, callback function provided as an argument, ignoring most callback arguments	5601961.0 Ops/sec
Array forEach, callback function provided as an argument	5600143.0 Ops/sec
Array forEach, callback function provided as a predefined variable	3423975.0 Ops/sec
for..of	733334.7 Ops/sec
for..in	4747800.0 Ops/sec
for loop	3430163.0 Ops/sec

Script Preparation code:

var array = new Array(100);

var fn = function(el, idx, arr) {
  el;
}

Tests:

Array forEach, callback function provided as an argument, ignoring most callback arguments
array.forEach(function(_el, idx, _arr) { array[idx]; });
Array forEach, callback function provided as an argument
array.forEach(function(el, idx, arr) { el; });
Array forEach, callback function provided as a predefined variable
array.forEach(fn);
for..of
for (const i of array) { array[i]; }
for..in
for (var i in array) { array[i]; }
for loop
for (var i = 0; i < array.length; i++) { array[i]; }