Benchmark: Array.prototype.concat vs spread operator for joining arrays incrementally

Script Preparation code:

var arrays = [
	Array(100).fill(1),
	Array(100).fill(2),
	Array(100).fill(3),
	Array(100).fill(4),
	Array(100).fill(5),
];

Tests:

Array.prototype.concat
let combinedArray = []; arrays.forEach((array) => { combinedArray = combinedArray.concat(array) })
spread operator
let combinedArray = []; arrays.forEach((array) => { combinedArray = [ ...combinedArray, ...array, ] })

Rendered benchmark preparation results:

Previous results

Test case name	Result
Array.prototype.concat
spread operator

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Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_1) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.0.1 Safari/605.1.15

Browser/OS: Safari 12 on Mac OS X 10.14.1

Test name	Executions per second
Array.prototype.concat	357272.1 Ops/sec
spread operator	117853.3 Ops/sec

Array.prototype.concat vs spread operator for joining arrays incrementally (version: 0)