Run results for: Array splice vs array assign

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:139.0) Gecko/20100101 Firefox/139.0

Browser: Firefox 139

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Object property assign

272K/s

Array splice

262K/s

View exact numbers

Test name	Executions per second
✓ Object property assign	272,161 Ops/sec
Array splice	261,998 Ops/sec

Script Preparation code:

var input = [];
for (var i = 0; i < 50000; i++) {
    input.push({
        id: i,
        data: 'something'
    })
}

Tests:

Array splice
const index = input.findIndex(val => val.id === 999); input.splice(index, 1, {id: 999, data: 'somethingElse'});
Object property assign
const index = input.findIndex(val => val.id === 999); input[index] = {id: 999, data: 'somethingElse'}