[Codewars] Coding Meetup #8 - Higher-Order Functions Series - Will all continents be represented? (6 kyu) / JavaScript

https://www.codewars.com/kata/58291fea7ff3f640980000f9

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DESCRIPTION:

You will be given a sequence 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.

 

코드

function allContinents(list) {
  return list.some(el => el.continent === 'Africa') && list.some(el => el.continent === 'Americas') && list.some(el => el.continent === 'Asia') && list.some(el => el.continent === 'Europe') && list.some(el => el.continent === 'Oceania');
}