Run results for: Array extension techniques

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Firefox/138.0

Browser: Firefox 138

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

spread concat -- output = [].concat(...batches)

10K/s

push spread -- output.push(...batch)

7K/s

push loop -- for (const v of batch) { output.push(v) }

6K/s

repeated concat -- output = output.concat(batch)

68/s

repeated spread -- output = [...output, ...batch]

14/s

View exact numbers

Test name	Executions per second
✓ spread concat -- output = [].concat(...batches)	9,530 Ops/sec
push spread -- output.push(...batch)	7,374 Ops/sec
push loop -- for (const v of batch) { output.push(v) }	5,661 Ops/sec
repeated concat -- output = output.concat(batch)	68 Ops/sec
repeated spread -- output = [...output, ...batch]	14 Ops/sec

Script Preparation code:

const batches = []
for (let i = 0; i < 1000; i++) {
  batches.push(new Array(10).fill(i))
}

Tests:

repeated spread -- output = [...output, ...batch]
let result = [] for (const batch of batches) { result = [...result, ...batch] } return result
repeated concat -- output = output.concat(batch)
let result = [] for (const batch of batches) { result = result.concat(batch) } return result
spread concat -- output = [].concat(...batches)
let result = [] result = result.concat(...batches) return result
push spread -- output.push(...batch)
let result = [] for (const batch of batches) { result.push(...batch) } return result
push loop -- for (const v of batch) { output.push(v) }
let result = [] for (const batch of batches) { for (const v of batch) { result.push(v) } } return result