Benchmark: large list of strings: spread operator vs Array.from + push vs slice + push vs flat

Script Preparation code:

const largeList = Array.from({length: 100_000}).map((_, idx)  => `${idx}`.padStart(30, '0'));

Tests:

spread operator
const newList = [...largeList, 'a new string'];
Array.from + push
const newList = Array.from(largeList); newList.push('a new string');
Slice + push
const newList = largeList.slice(); newList.push('a new string');
flat
const newList = [largeList, ['a new string']].flat();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
spread operator
Array.from + push
Slice + push
flat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 6 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser/OS: Chrome 135 on Windows

View result in a separate tab

spread operator

3K/s

Array.from + push

3K/s

Slice + push

3K/s

flat

821/s

View exact numbers

Test name	Executions per second
✓ spread operator	3,480 Ops/sec
Array.from + push	3,344 Ops/sec
Slice + push	3,197 Ops/sec
flat	821 Ops/sec

large list of strings: spread operator vs Array.from + push vs slice + push vs flat (version: 1)

Compare the new ES6 spread operator with the traditional concat() method and push

Comparing performance of: `spread operator vs Array.from + push vs Slice + push vs flat`

Created: 6 months ago by: Guest

Go to the latest result

spread operator

Array.from + push

Slice + push

flat

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

large list of strings: spread operator vs Array.from + push vs slice + push vs flat (version: 1)

Compare the new ES6 spread operator with the traditional concat() method and push

Comparing performance of: spread operator vs Array.from + push vs Slice + push vs flat

Created: 6 months ago by: Guest

Go to the latest result

spread operator

Array.from + push

Slice + push

flat

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `spread operator vs Array.from + push vs Slice + push vs flat`