Run results for: Merge 3 small arrays

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/113.0

Browser: Firefox 113

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Using array spread	5324139.0 Ops/sec
Using clone and push loop	10082558.0 Ops/sec
Using clone and push spread	4393178.5 Ops/sec
Using clone and push spread 2	3553577.8 Ops/sec
Using push spread	2945258.8 Ops/sec
Using array concat	7670045.0 Ops/sec
Using array concat (2)	3492119.2 Ops/sec

Script Preparation code:

var array1 = [];
var array2 = [];
var array3 = [];
for (let m = 0; m < 10; m++) {
  array1.push(m);
  array2.push(m + 10);
  array3.push(m + 20);
}

Tests:

Using array spread
let array = [...array1, ...array2, ...array3];
Using clone and push loop
let array = array1.slice(); for (let i = 0; i < array2.length; i++) { array.push(array2[i]); } for (let i = 0; i < array3.length; i++) { array.push(array3[i]); }
Using clone and push spread
let array = array1.slice(); array.push(...array2); array.push(...array3);
Using clone and push spread 2
let array = array1.slice(); array.push(...array2, ...array3);
Using push spread
let array = []; array.push(...array1, ...array2, ...array3);
Using array concat
let array = [].concat(array1, array2, array3);
Using array concat (2)
let array = [].concat(array1).concat(array2).concat(array3);

Run results for: Merge 3 small arrays

Merge 3 arrays of 10 elements

Using array spread

Using clone and push loop

Using clone and push spread

Using clone and push spread 2

Using push spread

Using array concat

Using array concat (2)