Run results for: Array extension techniques 3

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

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

315K/s

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

45K/s

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

40K/s

flat

13K/s

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

10K/s

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

3K/s

View exact numbers

Test name	Executions per second
✓ spread concat -- output = [].concat(...batches)	314,804 Ops/sec
push loop -- for (const v of batch) { output.push(v) }	45,435 Ops/sec
push spread -- output.push(...batch)	40,061 Ops/sec
flat	13,188 Ops/sec
repeated concat -- output = output.concat(batch)	9,547 Ops/sec
repeated spread -- output = [...output, ...batch]	3,121 Ops/sec

Script Preparation code:

const batches = []
for (let i = 0; i < 100; i++) {
  batches.push(new Array(100).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
flat
let result = [] result = batches.flat() return result