JSFiddle - React, Tailwind, and code Playground

by Amal Das

JavaScript

var arr =   [
  {
    "firstName": "San",
    "middleName": "Brit",
    "lastName": "Lee",
    "empId": 34535,
    "designation": "developer"
  },
  {
    "firstName": "Marie",
    "middleName": "Skłodowska",
    "lastName": "Curie",
    "empId": 23456,
    "designation": "scientist"
  },
  {
    "firstName": "Addy",
    "lastName": "Osmani",
    "empId": 67834,
    "designation": "developer"
  },
  {
    "firstName": "Eric",
    "middleName": "Emerson",
    "lastName": "Schmit",
    "empId": 23467,
    "designation": "manager"
  }
]

let output = arr.reduce((acc, curr) => {
	if(acc[curr.designation]){
  	acc[curr.designation].push(curr.firstName+' '+curr.lastName)
  } else {
  	acc[curr.designation] = [curr.firstName+' '+curr.lastName];
  }
  return acc;
},{})

console.log(output)