Run results for: JavaScript Object spread operator vs manual assignment

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Using manual assignment

163.3M/s

Using spread syntax

60.5M/s

View exact numbers

Test name	Executions per second
✓ Using manual assignment	163,326,736 Ops/sec
Using spread syntax	60,549,104 Ops/sec

Tests:

Using spread syntax
const input = { data1: '1', data2: '2', data3: '3', data4: '4' } const output = { ...input }; output.data5 = '5'
Using manual assignment
const input = { data1: '1', data2: '2', data3: '3', data4: '4' } const output = { data1: input.data1, data2: input.data2, data3: input.data3, data4: input.data4, }; output.data5 = '5'