[JavaScript 30일 챌린지] : 4일차

// Array.prototype.filter()
// 1. Filter the list of inventors for those who were born in the 1500's
const fifteen = inventors.filter(inventors => (inventors.year >= 1500 && inventors.year < 1600));
console.table(fifteen);

// Array.prototype.map()
// 2. Give us an array of the inventors first and last names
const fullNames = inventors.map(inventors => `${inventors.first} ${inventors.last}`);
console.log(fullNames);

// Array.prototype.sort()
// 3. Sort the inventors by birthdate, oldest to youngest
const ordered = inventors.sort((a, b) => a.year > b.year ? 1 : -1);
console.table(ordered);

// Array.prototype.reduce()
// 4. How many years did all the inventors live all together?
const totalYears = inventors.reduce((total, inventors) => {
  return total + (inventors.passed - inventors.year);
}, 0);

// 5. Sort the inventors by years lived
const oldest = inventors.sort(function (a, b) {
  const lastInventor = a.passed - a.year;
  const nextInventor = b.passed - b.year;
  return lastInventor > nextInventor ? -1 : 1;
});
console.table(oldest);

// 6. create a list of Boulevards in Paris that contain 'de' anywhere in the name
// https://en.wikipedia.org/wiki/Category:Boulevards_in_Paris


// 7. sort Exercise
// Sort the people alphabetically by last name
const alpha = people.sort((lastOne, nextOne) => {
  const [aLast, aFirst] = lastOne.split(', ');
  const [bLast, bFirst] = nextOne.split(', ');
  return aLast > bLast ? 1 : -1;
});

console.log(alpha);

// 8. Reduce Exercise
// Sum up the instances of each of these
const data = ['car', 'car', 'truck', 'truck', 'bike', 'walk', 'car', 'van', 'bike', 'walk', 'car', 'van', 'car', 'truck' ];

const transportation = data.reduce(function (obj, item) {
  if (!obj[item]) {
    obj[item] = 0;
  }
  obj[item]++;
  return obj;
}, {});

console.log(transportation);