Run results for: Fixed: Performance of uniqueBy using new Map or reducing to an object, also comparing for..in and Object.values for extracting values - More3

Compare performance between the native Object.values(obj) function vs the lodash _.values() option and a function that extracts the values of an object using a for...in loop.

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.102 Safari/537.36

Browser: Chrome 85

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
unique by map, extract with deconstruct	4935.3 Ops/sec
obj UniqueBy, extract with for...in loop	2386.4 Ops/sec
obj UniqueBy, extract with Object.values()	2535.3 Ops/sec
unique by map, extract with ArrayFrom	3974.4 Ops/sec

Script Preparation code:

function uniqueBy(list, predicate, extractor) {
 	const a = new Map(list.map(l => [predicate(l), l]))
    return extractor(a)
}

function extractorDeconstruct(iterator) {
	return [...iterator.values()]
}

function extractorArrayFrom(iterator) {
 	return Array.from(iterator) 
}

function objUniqueBy(list, predicate, extractor) {
    const a = list.reduce((acc, val) => Object.assign(acc, { [predicate(val)]: val }), {})
    return extractor(a)
}

function extractValuesForIn(obj) {
   const t = [];
   for(var key in obj) { t.push(obj[key]); }
   return t;
}

function extractValuesObject(obj) {
  return Object.values(obj);
}

function makeRange(n) {
  let range = []
  for (let i = 0; i < n; i++) {
    range.push(i)
  }
  return range
}

Tests:

unique by map, extract with deconstruct
const a = Object.assign(makeRange(3000).map(i => ({ a: i, b: 1})), makeRange(1000).map(i => ({ a: i, b: 2}))) uniqueBy(a, (x) => x['a'], extractorDeconstruct)
obj UniqueBy, extract with for...in loop
const a = Object.assign(makeRange(3000).map(i => ({ a: i, b: 1})), makeRange(1000).map(i => ({ a: i, b: 2}))) objUniqueBy(a, (x) => x['a'], extractValuesForIn);
obj UniqueBy, extract with Object.values()
const a = Object.assign(makeRange(3000).map(i => ({ a: i, b: 1})), makeRange(1000).map(i => ({ a: i, b: 2}))) objUniqueBy(a, (x) => x['a'], extractValuesObject);
unique by map, extract with ArrayFrom
const a = Object.assign(makeRange(3000).map(i => ({ a: i, b: 1})), makeRange(1000).map(i => ({ a: i, b: 2}))) uniqueBy(a, (x) => x['a'], extractorArrayFrom)

Run results for: Fixed: Performance of uniqueBy using new Map or reducing to an object, also comparing for..in and Object.values for extracting values - More3

Compare performance between the native Object.values(obj) function vs the lodash _.values() option and a function that extracts the values of an object using a for...in loop.

unique by map, extract with deconstruct

obj UniqueBy, extract with for...in loop

obj UniqueBy, extract with Object.values()

unique by map, extract with ArrayFrom