function learnJavaScript() {
  const friends = [
    { passport: '03005988', name: 'Joseph Francis Tribbiani Jr', age: 32, sex: 'm' },
    { passport: '03005989', name: 'Chandler Muriel Bing', age: 33, sex: 'm' },
    { passport: '03005990', name: 'Ross Eustace Geller', age: 33, sex: 'm' },
    { passport: '03005991', name: 'Rachel Karen Green', age: 31, sex: 'f' },
    { passport: '03005992', name: 'Monica Geller', age: 31, sex: 'f' },
    { passport: '03005993', name: 'Phoebe Buffay', age: 34, sex: 'f' }
  ]

  const names = friends.reduce((accumulator, friend) => `${accumulator} ${friend.name}, `, 'Friends: ')

  return names
}