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

Jump 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; }

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: 9 months 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

Test name	Executions per second
forEach	1468709.9 Ops/sec
for	3686427.0 Ops/sec
for optimized	3683025.0 Ops/sec
reduce	2979076.0 Ops/sec
while	4069421.8 Ops/sec
for in	160291.8 Ops/sec
for of	2687479.5 Ops/sec

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