Callback Functions at Runtime by Udacity FrontENDev

useMap-Filter_callback.js

/* Using filter()
 *
 * Using the musicData array and filter():
 *   - Return only album objects where the album's name is
 *     10 characters long, 25 characters long, or anywhere in between
 *   - Store the returned data in a new `results` variable
 *
 * Note:
 *   - Do not delete the musicData variable
 *   - Do not alter any of the musicData content
 */

const musicData = [
    { artist: 'Adele', name: '25', sales: 1731000 },
    { artist: 'Drake', name: 'Views', sales: 1608000 },
    { artist: 'Beyonce', name: 'Lemonade', sales: 1554000 },
    { artist: 'Chris Stapleton', name: 'Traveller', sales: 1085000 },
    { artist: 'Pentatonix', name: 'A Pentatonix Christmas', sales: 904000 },
    { artist: 'Original Broadway Cast Recording', 
      name: 'Hamilton: An American Musical', sales: 820000 },
    { artist: 'Twenty One Pilots', name: 'Blurryface', sales: 738000 },
    { artist: 'Prince', name: 'The Very Best of Prince', sales: 668000 },
    { artist: 'Rihanna', name: 'Anti', sales: 603000 },
    { artist: 'Justin Bieber', name: 'Purpose', sales: 554000 }
];

const results = musicData.filter( function collect(album) {
    return album.name.length > 9 && album.name.length < 26;
} );

console.log(results);

for the above filter method
const results = musicData.filter(function(album){ return album.name.length >= 10 && album.name.length < 25; });

for the filter method, this code also possible
const results = musicData.filter(album => album.name.length <= 25 && album.name.length >= 10);
console.log(results);