Run results for: Javascript uniqueBy key vs Javascript uniqueBy stringify

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser: Chrome 115

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Javascript uniqueBy key	12801382.0 Ops/sec
Javascript uniqueBy	968147072.0 Ops/sec

Script Preparation code:

var users = [
  { 'user': 'joey',  'age': 29 },
  { 'user': 'joey',  'age': 32 },
  { 'user': 'ross',    'age': 41 },
  { 'user': 'ross',    'age': 25 },
  { 'user': 'ross',    'age': 48 },
  { 'user': 'chandler', 'age': 39 },
  { 'user': 'chandler', 'age': 12 },
  { 'user': 'chandler', 'age': 41 }
]

Tests:

Javascript uniqueBy key
const uniqueBy = (array, key) => array.filter((value, index, self) => self.findIndex((item) => item[key] === value[key]) === index); let uniqued = uniqueBy(users, 'user');
Javascript uniqueBy
function removeDuplicatesFromArray(arr) { return arr.filter((value, index, self) => index === self.findIndex(obj => JSON.stringify(obj) === JSON.stringify(value))); }