JavaScript EC6 test

ec6.js

var data = [{
  "firstName": "Loraine",
  "lastName": "Rosenzveig",
  "gender": "Female"
}, {
  "firstName": "Shandeigh",
  "lastName": "Pomroy",
  "gender": "Female"
}, {
  "firstName": "Skipper",
  "lastName": "Dablin",
  "gender": "Male"
}, {
  "firstName": "Nikolaos",
  "lastName": "Bushrod",
  "gender": "Male"
}, {
  "firstName": "Jaimie",
  "lastName": "Breache",
  "gender": "Male"
}, {
  "firstName": "Dayle",
  "lastName": "Samart",
  "gender": "Female"
}, {
  "firstName": "Jerrie",
  "lastName": "Martinolli",
  "gender": "Female"
}, {
  "firstName": "Albertine",
  "lastName": "Schowenburg",
  "gender": "Female"
}, {
  "firstName": "Tatiania",
  "lastName": "Rumming",
  "gender": "Female"
}, {
  "firstName": "Somerset",
  "lastName": "Wrenn",
  "gender": "Male"
}]

/*
Using the data above, create a new array containing all the names of females.
The resulting array should contain strings where first and last name are concatinated.
Such as ["Loraine Rosenzveig", "Shandeigh Pomroy", ...etc]
*/
/*
var females = data.map(function(d){
  if (d.gender == 'Female') {
    return d.firstName + ' ' + d.lastName;
  }
});
*/

// Bobby's improvement
var females = data.filter(d => d.gender == 'Female');
females = females.map(fems => fems.firstName + ' ' + fems.lastName);
console.log(females);

// OR: 
const result = data
  .filter(x => x.gender === 'Female')
  .map(x => x.firstName + ' ' + x.lastName)

// OR:
const isFemale = x => x.gender === 'Female'
const combineNames = x => x.firstName + ' ' + x.lastName
const result = data
  .filter(isFemale)
  .map(combineNames)