Run results for: Array splice vs object assign

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Object property assign

89.1M/s

Array splice

1.4M/s

ES6 Object Spread

45K/s

View exact numbers

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'});
ES6 Object Spread
input = { ...input, [999]: {id: 999, data: 'somethingElse'} }
Object property assign
input[999] = {id: 999, data: 'somethingElse'}