Run results for: JavaScript Object spread operator vs manual assignment

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Firefox/138.0

Browser: Firefox 138

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Using manual assignment

80.5M/s

Using spread syntax

13.0M/s

View exact numbers

Test name	Executions per second
✓ Using manual assignment	80,488,016 Ops/sec
Using spread syntax	12,964,134 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'