Reduce your fears about .reduce() - twentySomethingsLongFullNames.js

twentySomethingsLongFullNames.js

const isInTwenties = user => user.age >= 20 && user.age < 30;
const makeFullName = user => `${user.firstName} ${user.lastName}`;
const isAtLeastTenChars = fullName => fullName.length >= 10;

const twentySomethingsLongFullNames = users.filter(isInTwenties)
                                           .map(makeFullName)
                                           .filter(isAtLeastTenChars);