Run results for: Test 2 function in vanilla js

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36 Edg/107.0.1418.35

Browser: Chrome 107

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
reduce and map	168206.3 Ops/sec
reduce and findIndex	183836.1 Ops/sec

Script Preparation code:

var array = [
  {
    name: "Jules",
    age: 2,
    famille: "adam"
  },
  {
    name: "John",
    famille: "dupont"
  },
  {
    name: "Julie",
    famille: "dupont"
  },
  {
    name: "Juliette"
  }
];

Tests:

reduce and map
const result = Object.values( array.reduce((acc, obj) => { if (obj.hasOwnProperty("famille")) { if (!acc.hasOwnProperty(obj.famille)) { acc[obj.famille] = { prenom: [], famille: obj.famille }; } acc[obj.famille].prenom.push(obj.name); } return acc; }, {}) ).map((group) => { return { prenom: group.prenom, famille: group.famille }; }); console.log(result);
reduce and findIndex
const result = array.reduce((acc, curr) => { let index = acc.findIndex((item) => item.famille === curr.famille); if (index !== -1) { acc[index].prenom.push(curr.name); } else { acc.push({ prenom: [curr.name], famille: curr.famille }); } return acc; }, []); console.log(result);

Run results for: Test 2 function in vanilla js

reduce and map

reduce and findIndex