Run results for: map vs. map arrow vs for vs. for in vs. forEach - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36

Browser: Chrome 137

Operating system: Windows

Device Platform: Desktop

Date tested: 11 months ago

Test name	Executions per second
map	4068.4 Ops/sec
for in	3374.5 Ops/sec
for	5843.6 Ops/sec
forEach	6224.3 Ops/sec
map arrow	9166.0 Ops/sec

Script Preparation code:

var a = Array(10000).fill(null).map((a, index) => `foo  ${index}`)

Tests:

map
var b = a.map(function(c) { return `${c}+1` ; });
for in
var b = []; for (var i in a) { b.push(`${a[i]}+1`); }
for
var b = []; for (var i = 0; i < a.length; i++) { b.push(`${a[i]}+1`); }
forEach
var b = []; a.forEach(function(c) { b.push(`${c}+1`); });
map arrow
var b = a.map(c => `${c}+1`);