js-search-and-reduce

js-search-and-reduce.js

// https://twitter.com/forwebdev/status/789538916898660352
const userIds = [1, 5, 1, 2, 9, 9, 6, 4, 3, 5];
console.log(userIds.slice().sort();
// -> [1, 1, 2, 3, 4, 5, 5, 6, 9, 9]
function getUniqueItems(array) {
  const = uniqueItemsHash = array.reduce((acc, item) => {
    acc[item] = item;
    return acc;
  }, {});
  
  return Object.keys(uniqueItemsHash).map(key => uniqueItemsHash[key]);
}
const uniqueUsersIds = getUniqueItems(userIds);
console.log(uniqueUsersIds.slice().sort());
// -> [1, 2, 3, 4, 5, 6, 9]
            
// https://twitter.com/forwebdev/status/789477769247854592
// for primitives
const userIds = [1, 5, 1, 2, 9, 9, 6, 4, 3, 5];
const uniqueUsersIds = userIds.filter((id, index, array) => array.indexOf(id) === index);
console.log(uniqueUsersIds.slice().sort());
// -> [1, 2, 3, 4, 5, 6, 9]