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 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Mobile Safari/537.36

Browser: Chrome Mobile 121

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

For loop

2.1M/s

.fill(0).map()

710K/s

.fill(true).map()

665K/s

.fill(null).map()

663K/s

.fill(undefined).map()

658K/s

.fill("").map()

647K/s

Array.from().map()

95K/s

Array.from() only

84K/s

View exact numbers

Test name	Executions per second
✓ For loop	2,074,137 Ops/sec
.fill(0).map()	709,765 Ops/sec
.fill(true).map()	664,949 Ops/sec
.fill(null).map()	662,721 Ops/sec
.fill(undefined).map()	658,143 Ops/sec
.fill("").map()	647,464 Ops/sec
Array.from().map()	95,427 Ops/sec
Array.from() only	84,436 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