Run results for: mapvalues reduce

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.97 Safari/537.36

Browser: Chrome 83

Operating system: Mac OS X 10.15.5

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
_.mapValues(collection, () => "a")	43020.8 Ops/sec
Object.keys(collection).reduce( (acc, item) => ({ ...acc, [item]: "a", }), {} )	32801.5 Ops/sec

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.15/lodash.min.js"></script>

Script Preparation code:

var collection = [1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, ]

Tests:

_.mapValues(collection, () => "a")
_.mapValues(collection, () => "a")
Object.keys(collection).reduce( (acc, item) => ({ ...acc, [item]: "a", }), {} )
Object.keys(collection).reduce( (acc, item) => ({ ...acc, [item]: "a", }), {} )

Run results for: mapvalues reduce

_.mapValues(collection, () => "a")

Object.keys(collection).reduce( (acc, item) => ({ ...acc, [item]: "a", }), {} )