Run results for: filter.map vs reduce 2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/83.0

Browser: Firefox 83

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
filter.map	5226217.5 Ops/sec
reduce 1	10047713.0 Ops/sec
reduce 2	1989756.5 Ops/sec

Script Preparation code:

arr = [{ foo: true, bar: 'a' }, { foo: false, bar: 'b' }, { foo: false, bar: 'c'},
{ foo: true, bar: 'a' }, { foo: false, bar: 'b' }, { foo: false, bar: 'c' },
{ foo: true, bar: 'a' }, { foo: false, bar: 'b' }, { foo: false, bar: 'c' }];

Tests:

filter.map
const result = arr .filter((item) => !item.foo) .map((item) => item.bar);
reduce 1
const result = arr.reduce((acc, item) => { if (!item.foo) { acc.push(item.bar); } return acc; }, []);
reduce 2
const result = arr.reduce((acc, item) => acc.concat(!item.foo ? item.bar : []), []);
reduce 3
const result = arr.reduce((acc, item) => item.foo ? acc : [...acc, item.bar], []);

Run results for: filter.map vs reduce 2

filter.map

reduce 1

reduce 2

reduce 3