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: one year ago

Array forEach, callback function provided as an argument, ignoring most callback arguments

5.6M/s

Array forEach, callback function provided as an argument

5.6M/s

for..in

4.7M/s

for loop

3.4M/s

Array forEach, callback function provided as a predefined variable

3.4M/s

for..of

733K/s

View exact numbers

Test name	Executions per second
✓ Array forEach, callback function provided as an argument, ignoring most callback arguments	5,601,961 Ops/sec
Array forEach, callback function provided as an argument	5,600,143 Ops/sec
for..in	4,747,800 Ops/sec
for loop	3,430,163 Ops/sec
Array forEach, callback function provided as a predefined variable	3,423,975 Ops/sec
for..of	733,335 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]; }