Benchmark: Filter out null and map nested object with flatMap() vs map().filter()

Script Preparation code:

var arr = [];
var id = 0;

while (id <= 1_000_000) {
  id++;
  arr[id] = id % 10 === 0
    ? { id, data: null }
    : { id, data: { id } };
}

Tests:

map().filter()
arr.map(it => it.data).filter(it => it !== null)
flatMap()
arr.flatMap(it => it.data != null ? [it.data] : [])
filter().map()
arr.filter(it => it.data !== null).map(it => it.data)

Historical Performance Data aggregated from 6 community runs

Desktop Results:

Chrome 6 runs

map().filter()

108.4M/s

filter().map()

106.9M/s

flatMap()

52.7M/s

Fastest: map().filter() (2.1x faster)

View exact numbers

✓ map().filter(): 108,442,112 ops/sec
• filter().map(): 106,865,296 ops/sec
• flatMap(): 52,657,052 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map().filter()
flatMap()
filter().map()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

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

Browser/OS: Firefox 138 on Windows

View result in a separate tab

map().filter()

17/s

filter().map()

15/s

flatMap()

12/s

View exact numbers

Test name	Executions per second
✓ map().filter()	17 Ops/sec
filter().map()	15 Ops/sec
flatMap()	12 Ops/sec

Filter out null and map nested object with flatMap() vs map().filter() (version: 5)

flatMap vs filter map

Comparing performance of: `map().filter() vs flatMap() vs filter().map()`

Created: one year ago by: Registered User

Go to the latest result

map().filter()

flatMap()

filter().map()

Historical Performance Data aggregated from 6 community runs

Desktop Results:

Chrome 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Filter out null and map nested object with flatMap() vs map().filter() (version: 5)

flatMap vs filter map

Comparing performance of: map().filter() vs flatMap() vs filter().map()

Created: one year ago by: Registered User

Go to the latest result

map().filter()

flatMap()

filter().map()

Historical Performance Data aggregated from 6 community runs

Desktop Results:

Chrome 6 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Related benchmarks

Comparing performance of: `map().filter() vs flatMap() vs filter().map()`