Run results for: for vs for in vs for of vs forEach (no length)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36

Browser: Chrome 134

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

for of

4.3M/s

forEach

4.1M/s

for

1.1M/s

for in

81K/s

View exact numbers

Script Preparation code:

var data = [... new Array(1000)].map((x,i) => i);

Tests:

forEach
let result = 0; data.forEach(x => { result = x; });
for of
let result = 0; for (let x of data) { result = x; }
for in
let result = 0; for (let i in data) { result = data[i]; }
for
let result = 0; let len = data.length for (let i = 0; i < len; i++) { result = data[i]; }