Run results for: array.length = 0 and push vs [...data]

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_0_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.0.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.0.1

Device Platform: Mobile

Date tested: one year ago

array = [...data]

10.7M/s

array length = 0 and push

6.6M/s

View exact numbers

Test name	Executions per second
✓ array = [...data]	10,729,565 Ops/sec
array length = 0 and push	6,596,532 Ops/sec

Script Preparation code:

var arr = [1,2,3,4];
var data = arr.slice()

Tests:

array length = 0 and push
arr.length = 0 arr.push(...data)
array = [...data]
arr = [...data]