Run results for: lodash flatten vs reduce array

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) GSA/345.2.700885593 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.2

Device Platform: Mobile

Date tested: one year ago

Benchmark engine: Benchmark.js

flatten

53K/s

reduce

1K/s

View exact numbers

Test name	Executions per second
✓ flatten	52,984 Ops/sec
reduce	1,186 Ops/sec

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Script Preparation code:

myList = [];

for (let i = 0; i < 100; i++) {
  const arr = [];
  for (var n = 0; n < 100; n++) {
    arr.push({ ['key' + n]: n });
  }
  myList.push(arr)
}

Tests:

flatten
_.flatten(myList)
reduce
myList.reduce((acc, item) => { return [...acc, ...item]; }, [])