Benchmark: forEach vs for len vs for in vs for of fix

forEach vs for len vs for in vs for of fix (version: 1)

created based off of an archived jsperf benchmark: http://web.archive.org/web/20191008221700/https://jsperf.com/foreach-vs-for-loop-vs-for-in-vs-for-of-vs-babel-for-of change var to let. for of returns the value directly. So you don't get value from testData array.

Comparing performance of: `forEach vs for vs for optimized vs reduce vs while vs for in vs for of`

Created: one year ago by: Registered User

Go to the latest result

HTML Preparation code:

<script>
    Benchmark.prototype.setup = function() {
        var testData = [];
        for (var i = 0; i < 100; i++) {
            testData.push(i);
        }
    };
</script>

Tests:

forEach
let res = 0; testData.forEach(function(x) { res += x; });
for
let res = 0; for (let i = 0; i < testData.length; i++) { res += testData[i]; }
for optimized
let res = 0; for (let i = 0, len = testData.length; i < len; i++) { res += testData[i]; }
reduce
var res = testData.reduce(function(sum, x) { return sum + x; }, 0);
while
var res = 0; var i = testData.length; while (i--) { res += testData[i]; }
for in
var res = 0; for (let data in testData) { res += testData[data]; }
for of
var res = 0; for (var data of testData) { res += data; }

Historical Performance Data aggregated from 10 community runs

Desktop Results:

Chrome 10 runs

for optimized

20.5M/s

for

19.6M/s

reduce

13.8M/s

while

12.6M/s

forEach

7.6M/s

for of

7.5M/s

for in

529K/s

Fastest: for optimized (38.7x faster)

View exact numbers

✓ for optimized : 20,464,672 ops/sec
• for: 19,648,852 ops/sec
• reduce : 13,779,491 ops/sec
• while: 12,564,536 ops/sec
• forEach: 7,618,320 ops/sec
• for of: 7,520,770 ops/sec
• for in: 528,667 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
forEach
for
for optimized
reduce
while
for in
for of

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 138 on Android

View result in a separate tab

while

4.1M/s

for

3.7M/s

for optimized

3.7M/s

reduce

3.0M/s

for of

2.7M/s

forEach

1.5M/s

for in

160K/s

View exact numbers

Test name	Executions per second
✓ while	4,069,422 Ops/sec
for	3,686,427 Ops/sec
for optimized	3,683,025 Ops/sec
reduce	2,979,076 Ops/sec
for of	2,687,480 Ops/sec
forEach	1,468,710 Ops/sec
for in	160,292 Ops/sec

forEach vs for len vs for in vs for of fix (version: 1)

created based off of an archived jsperf benchmark: http://web.archive.org/web/20191008221700/https://jsperf.com/foreach-vs-for-loop-vs-for-in-vs-for-of-vs-babel-for-of change var to let. for of returns the value directly. So you don't get value from testData array.

Comparing performance of: forEach vs for vs for optimized vs reduce vs while vs for in vs for of

Created: one year ago by: Registered User

Go to the latest result

forEach

for

for optimized

reduce

while

for in

for of

Historical Performance Data aggregated from 10 community runs

Desktop Results:

Chrome 10 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `forEach vs for vs for optimized vs reduce vs while vs for in vs for of`