Benchmark: for vs foreach vs for..in vs for..of with Map and 1 million entry

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

const map = new Map();
for (let i = 0; i < 1000000; i++) {
    map.set(i, Math.random() * 1000);
}

Tests:

for-i
for (let i = 0; i < map.size; i++) { const value = map.get(i); const str = value.toString(10); }
forEach
map.forEach((value, key) => { const str = value.toString(10); });
for-of
for (const [key, value] of map) { const str = value.toString(10); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for-i
forEach
for-of

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 26 days ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 26_5_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) EdgiOS/149.0.4022.96 Version/26.0 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 26 on iOS 26.5.0

View result in a separate tab

forEach

108/s

for-of

98/s

for-i

43/s

View exact numbers

Test name	Executions per second
✓ forEach	108 Ops/sec
for-of	98 Ops/sec
for-i	43 Ops/sec

for vs foreach vs for..in vs for..of with Map and 1 million entry (version: 2)

Compare loop performance with a small load with Map object and 1 million entry Note: for-in do not work with Map

Comparing performance of: `for-i vs forEach vs for-of`

Created: 28 days ago by: Registered User

Go to the latest result

for-i

forEach

for-of

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

for vs foreach vs for..in vs for..of with Map and 1 million entry (version: 2)

Compare loop performance with a small load with Map object and 1 million entry Note: for-in do not work with Map

Comparing performance of: for-i vs forEach vs for-of

Created: 28 days ago by: Registered User

Go to the latest result

for-i

forEach

for-of

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `for-i vs forEach vs for-of`