Benchmark: reduce vs assigning with a forEach

Tests:

Creating an object with .reduce()
const oldObject = { one: 1, two: 2, three: 3, four: 4, five: 5 } const newObject = Object.keys(oldObject).reduce( (acc, key) => { if (key.includes('t')) return { ...acc, [key]: true } return acc }, {}, )
Assigning object properties with .forEach()
const newObject = {} const oldObject = { one: 1, two: 2, three: 3, four: 4, five: 5 } Object.keys(oldObject).forEach(key => { if (key.includes('t')) newObject[key] = true })

Rendered benchmark preparation results:

Previous results

Test case name	Result
Creating an object with .reduce()
Assigning object properties with .forEach()

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Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.122 Safari/537.36

Browser/OS: Chrome 81 on Mac OS X 10.15.5

Test name	Executions per second
Creating an object with .reduce()	1541426.0 Ops/sec
Assigning object properties with .forEach()	2900836.0 Ops/sec

reduce vs assigning with a forEach (version: 0)