set.md

[JavaScript] - Set

SOURCE

The Set object lets you store unique values of any type, whether primitive values or object references.

const ordersSet = new Set([
  'Pasta',
  'Pizza',
  'Pizza',
  'Risotto',
  'Pasta',
  'Pizza',
]);
console.log(ordersSet); // Set(3) {'Pasta', 'Pizza', 'Risotto'}
console.log(new Set('Jonas')); // Set(5) {'J', 'o', 'n', 'a', 's'}

console.log(ordersSet.size);
console.log(ordersSet.has('Pizza'));
console.log(ordersSet.has('Bread'));

ordersSet.add('Garlic Bread');
ordersSet.add('Garlic Bread');
ordersSet.delete('Risotto');
// ordersSet.clear();

console.log(ordersSet);

for (const order of ordersSet) console.log(order);

// remove duplicate value out of an array
const staff = ['Waiter', 'Chef', 'Waiter', 'Manager', 'Chef', 'Waiter'];
const staffUnique = [...new Set(staff)];
console.log(staffUnique); // (3) ['Waiter', 'Chef', 'Manager']

console.log(new Set('jonasschmedtmann').size); // there 11 unique characters in this string