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_2_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/21C66 Twitter for iPhone/10.26

Browser: Mobile Safari 17

Operating system: iOS 17.2.1

Device Platform: Mobile

Date tested: 2 years ago

Array.from() only

4.1M/s

Array.from().map()

1.9M/s

.fill(undefined).map()

1.2M/s

.fill(true).map()

1.2M/s

.fill(null).map()

1.2M/s

.fill("").map()

1.2M/s

View exact numbers

Test name	Executions per second
✓ Array.from() only	4,094,052 Ops/sec
Array.from().map()	1,883,321 Ops/sec
.fill(undefined).map()	1,235,991 Ops/sec
.fill(true).map()	1,234,614 Ops/sec
.fill(null).map()	1,234,016 Ops/sec
.fill("").map()	1,233,793 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);