Run results for: JavaScript spread operator vs Object.fromentries performance

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Browser: Firefox 133

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Using the spread operator

12.1M/s

Using Object.assign

6.4M/s

View exact numbers

Test name	Executions per second
✓ Using the spread operator	12,067,649 Ops/sec
Using Object.assign	6,387,608 Ops/sec

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world' } const secondObject = { moreData: 'foo bar' } const a1 = Object.entries(firstObject) const a2 = Object.entries(secondObject) const finalObject = Object.fromEntries(a1.concat(a2));