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 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Browser: Chrome 138

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

For loop

37.1M/s

.fill(0).map()

4.7M/s

.fill("").map()

4.3M/s

.fill(undefined).map()

4.3M/s

.fill(true).map()

4.2M/s

.fill(null).map()

4.2M/s

Array.from().map()

439K/s

Array.from() only

393K/s

View exact numbers

Test name	Executions per second
✓ For loop	37,116,912 Ops/sec
.fill(0).map()	4,714,552 Ops/sec
.fill("").map()	4,258,787 Ops/sec
.fill(undefined).map()	4,257,582 Ops/sec
.fill(true).map()	4,243,179 Ops/sec
.fill(null).map()	4,221,850 Ops/sec
Array.from().map()	438,687 Ops/sec
Array.from() only	392,602 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