Coding Meetup #8 - Higher-Order Functions Series - Will all continents be represented?.js

/*
Description:
You will be given an array of objects (associative arrays in PHP) representing data about developers who have signed up to attend the next coding meetup that you are organising.

Your task is to return:

true if all of the following continents / geographic zones will be represented by at least one developer: 'Africa', 'Americas', 'Asia', 'Europe', 'Oceania'.
false otherwise.
For example, given the following input array:

var list1 = [
  { firstName: 'Fatima', lastName: 'A.', country: 'Algeria', continent: 'Africa', age: 25, language: 'JavaScript' },
  { firstName: 'Agustín', lastName: 'M.', country: 'Chile', continent: 'Americas', age: 37, language: 'C' },
  { firstName: 'Jing', lastName: 'X.', country: 'China', continent: 'Asia', age: 39, language: 'Ruby' },
  { firstName: 'Laia', lastName: 'P.', country: 'Andorra', continent: 'Europe', age: 55, language: 'Ruby' },
  { firstName: 'Oliver', lastName: 'Q.', country: 'Australia', continent: 'Oceania', age: 65, language: 'PHP' },
];
your function should return true as there is at least one developer from the required 5 geographic zones.

Notes:

The input array and continent names will always be valid and formatted as in the list above for example 'Africa' will always start with upper-case 'A'.




This kata is part of the Coding Meetup series which includes a number of short and easy to follow katas which have been designed to allow mastering the use of higher-order functions. In JavaScript this includes methods like: forEach, filter, map, reduce, some, every, find, findIndex. Other approaches to solving the katas are of course possible.
*/
function allContinents(list) {
  return ['Africa', 'Americas', 'Asia', 'Europe', 'Oceania'].every(x => list.some(y => x==y.continent));
}