Run results for: fill then map (with null/undefined/""/0) vs for loop vs array.from - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Android 10; Mobile; rv:122.0) Gecko/122.0 Firefox/122.0

Browser: Firefox Mobile 122

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

For loop

13.6M/s

Array.from() only

988K/s

Array.from().map()

488K/s

.fill(0).map()

414K/s

.fill(true).map()

412K/s

.fill(null).map()

404K/s

.fill(undefined).map()

404K/s

.fill("").map()

403K/s

View exact numbers

Test name	Executions per second
✓ For loop	13,581,829 Ops/sec
Array.from() only	987,806 Ops/sec
Array.from().map()	488,243 Ops/sec
.fill(0).map()	414,427 Ops/sec
.fill(true).map()	411,614 Ops/sec
.fill(null).map()	404,457 Ops/sec
.fill(undefined).map()	404,310 Ops/sec
.fill("").map()	402,909 Ops/sec

Tests:

Array.from() only
Array.from({ length: 100 }, (_, i) => i+i);
Array.from().map()
Array.from({ length: 100 }).map((_, i) => i+i);
.fill("").map()
Array(100).fill("").map((_, i) => i+i);
.fill(null).map()
Array(100).fill(null).map((_, i) => i+i);
.fill(undefined).map()
Array(100).fill(null).map((_, i) => i+i);
.fill(true).map()
Array(100).fill(true).map((_, i) => i+i);
.fill(0).map()
Array(100).fill(0).map((_, i) => i+i);
For loop
const a = new Array(100) for(let i = 0; i < a.lenght; i++) a[i] = i+i