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

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.3 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 17

Operating system: iOS 17.3

Device Platform: Mobile

Date tested: 2 years ago

Array.from() only

3.6M/s

Array.from().map()

1.8M/s

.fill(null).map()

1.2M/s

.fill(undefined).map()

1.2M/s

.fill(true).map()

1.2M/s

.fill("").map()

1.2M/s

View exact numbers

Test name	Executions per second
✓ Array.from() only	3,600,850 Ops/sec
Array.from().map()	1,755,612 Ops/sec
.fill(null).map()	1,159,882 Ops/sec
.fill(undefined).map()	1,158,502 Ops/sec
.fill(true).map()	1,157,961 Ops/sec
.fill("").map()	1,152,842 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);