Run results for: Array.prototype.concat vs spread operator (large, small diff

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser: Chrome 117

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Array.prototype.concat small	8203136.0 Ops/sec
spread operator (small)	11363364.0 Ops/sec
Array.prototype.concat (large)	1330608.4 Ops/sec
spread operator (large)	126816.5 Ops/sec

Script Preparation code:

// preparation
var a = Array.from({length: 1000}).map((_, i)=>`${i}`);
var b = Array.from({length: 2000}).map((_, i)=>`${i}`);
var aSmall = ['a', 'b', 'c', 'd'];
var bSmall = ['e', 'f', 'g', 'h', 'i'];

Tests:

Array.prototype.concat small
aSmall.concat(bSmall);
spread operator (small)
[...aSmall, ...bSmall]
Array.prototype.concat (large)
a.concat(b);
spread operator (large)
[...a, ...b]

Run results for: Array.prototype.concat vs spread operator (large, small diff

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

Array.prototype.concat small

spread operator (small)

Array.prototype.concat (large)

spread operator (large)