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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser: Chrome 119

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

.fill(true).map()

2.8M/s

.fill("").map()

2.8M/s

.fill(undefined).map()

2.8M/s

.fill(null).map()

2.8M/s

Array.from().map()

380K/s

Array.from() only

345K/s

View exact numbers

Test name	Executions per second
✓ .fill(true).map()	2,847,710 Ops/sec
.fill("").map()	2,800,939 Ops/sec
.fill(undefined).map()	2,792,708 Ops/sec
.fill(null).map()	2,778,600 Ops/sec
Array.from().map()	380,070 Ops/sec
Array.from() only	344,793 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);