74 lines
1.6 KiB
JavaScript
74 lines
1.6 KiB
JavaScript
// @ts-check
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//
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// The line above enables type checking for this file. Various IDEs interpret
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// the @ts-check directive. It will give you helpful autocompletion when
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// implementing this exercise.
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/**
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* Removes duplicate tracks from a playlist.
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*
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* @param {string[]} playlist
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* @returns {string[]} new playlist with unique entries
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*/
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export function removeDuplicates(playlist) {
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let list = [...new Set(playlist)];
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return list;
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}
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/**
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* Checks whether a playlist includes a track.
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*
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* @param {string[]} playlist
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* @param {string} track
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* @returns {boolean} whether the track is in the playlist
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*/
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export function hasTrack(playlist, track) {
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let list = new Set(playlist);
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return list.has(track);
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}
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/**
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* Adds a track to a playlist.
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*
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* @param {string[]} playlist
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* @param {string} track
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* @returns {string[]} new playlist
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*/
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export function addTrack(playlist, track) {
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let list = new Set(playlist);
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list.add(track);
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return Array.from(list);
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}
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/**
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* Deletes a track from a playlist.
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*
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* @param {string[]} playlist
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* @param {string} track
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* @returns {string[]} new playlist
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*/
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export function deleteTrack(playlist, track) {
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let list = new Set(playlist);
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list.delete(track);
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return Array.from(list)
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}
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/**
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* Lists the unique artists in a playlist.
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*
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* @param {string[]} playlist
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* @returns {string[]} list of artists
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*/
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export function listArtists(playlist) {
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let list = new Set(playlist);
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let artists = new Set;
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var artist;
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for (let song of list)
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{
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artist = song.split('- ');
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artists.add(artist[1]);
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}
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return Array.from(artists);
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}
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