Benchmark: JS insert at index spread vs Splice

Script Preparation code:

const ITERATIONS = 500000;
var index = ITERATIONS/2;
var n = Math.random();

var list = [];
for (let i = 0; i < length; i += 1) {
  list.push(Math.random());
}

Tests:

Array update with spread operator
const clone = [ ...list.slice(0, index), n, ...list.slice(index + 1), ];
Array update with slice and assign
const clone = list.slice(); clone[index] = n;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array update with spread operator
Array update with slice and assign

Fastest: N/A

Slowest: N/A

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Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Array update with spread operator	2750849.0 Ops/sec
Array update with slice and assign	2455773.0 Ops/sec

JS insert at index spread vs Splice (version: 0)

Comparing performance of: Array update with spread operator vs Array update with slice and assign

Created: 3 years ago by: Guest

Jump to the latest result

Array update with spread operator

Array update with slice and assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A