Run results for: Preinitialized array size vs Push operations to an empty one.

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/95.0.4638.54 Safari/537.36

Browser: Chrome 95

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Preinitialized size - large difference	4499.9 Ops/sec
Push	7527.0 Ops/sec
Preinitialized size - small difference	8231.4 Ops/sec
Preinitilized size - no difference	8265.1 Ops/sec

Tests:

Preinitialized size - large difference
let arr = new Array(100000) for (var i=0; i<1000; i++) { arr[i] = Math.random; } arr = arr.slice(0, 1000)
Push
let arr =[] for (var i=0; i<1000; i++) { arr.push(Math.random); }
Preinitialized size - small difference
let arr = new Array(1200) for (var i=0; i<1000; i++) { arr[i] = Math.random; } arr = arr.slice(0, 1000)
Preinitilized size - no difference
let arr = new Array(1000) for (var i=0; i<1000; i++) { arr[i] = Math.random; }