Run results for: spread large array (50000 elements) performance (vs slice, splice, concat, for)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0

Browser: Firefox 102

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Splice	15819199.0 Ops/sec
Slice	27087400.0 Ops/sec
Concat	19440736.0 Ops/sec
Spread	92087680.0 Ops/sec
For cycle with preallocation	66195216.0 Ops/sec

Script Preparation code:

testArray = [];
for (let i = 0; i < 50000; i++) testArray.push(i)

Tests:

Splice
const newTestArray = testArray.splice(0);
Slice
const newTestArray = testArray.slice();
Concat
const newTestArray = testArray.concat();
Spread
const newTestArray = [...testArray];
For cycle with preallocation
const testArrLen = testArray.length; const resArr = new Array(testArrLen); for (let i = 0; i < testArrLen; i++) { resArr[i] = testArray[i]; }