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JavaScript Object-Oriented JavaScript (2015) Constructor Functions and Prototypes Making the UI Work

Martina Carrington
Martina Carrington
15,754 Points
Posted by Martina Carrington
Martina Carrington
15,754 Points

my song won't show

i probably did something wrong on the music player . keep saying this on the JavaScript console a error Playlist.prototype.add = function(song) { this.songs.push(song); }; . now i have a blank music player

Hayley Swimelar
Hayley Swimelar
7,124 Points

Can you post your code so that we can have a better understanding of what might be wrong?

5 Answers

monty
monty
9,167 Points
monty
monty
9,167 Points

In your playlist.js, add an (s) to this.song[i].toHTML(); so that your renderInElement will look like this:

Playlist.prototype.renderInElement = function(list){
  list.innerHTML = "";
  for(var i = 0; i < this.songs.length; i++){
    list.innerHTML += this.songs[i].toHTML();
  }
monty
monty
9,167 Points
monty
monty
9,167 Points

list.innerHTML += this.songs[i].toHTML();

Martina Carrington
Martina Carrington
15,754 Points
Martina Carrington
Martina Carrington
15,754 Points

Playlist.js music player

function Playlist() {
  this.song = [];
  this.nowPlayingIndex = 0;

}

Playlist.prototype.add = function(song) {
  this.songs.push(song);
};

Playlist.prototype.play = function() {
  var currentSong = this.songs[this.nowPlayingIndex];
};

Playlist.prototype.stop = function(){
var currentSong = this.songs[this.nowPlayingIndex];
  currentSong.stop();
};

Playlist.prototype.next = function() {
  this.stop();
  this.nowPlayingIndex++;
  if(this.nowPlayingIndex === this.songs.length) {
  this.nowPlayingIndex = 0;
  }
    this.play();
};

Playlist.prototype.renderInElement = function(list) {
list.innerHTML = "";
for(var i = 0; i < this.songs.length; i++) {
  list.innerHTML += this.song[i].toHTML();

  }
};
Martina Carrington
Martina Carrington
15,754 Points
Martina Carrington
Martina Carrington
15,754 Points

@Hayley Swimelar

function Playlist() {
  this.song = [];
  this.nowPlayingIndex = 0;

}

Playlist.prototype.add = function(song) {
  this.songs.push(song);
};

Playlist.prototype.play = function() {
  var currentSong = this.songs[this.nowPlayingIndex];
};

Playlist.prototype.stop = function(){
var currentSong = this.songs[this.nowPlayingIndex];
  currentSong.stop();
};

Playlist.prototype.next = function() {
  this.stop();
  this.nowPlayingIndex++;
  if(this.nowPlayingIndex === this.songs.length) {
  this.nowPlayingIndex = 0;
  }
    this.play();
};

Playlist.prototype.renderInElement = function(list) {
list.innerHTML = "";
for(var i = 0; i < this.songs.length; i++) {
  list.innerHTML += this.song[i].toHTML();

  }
};
Iain Simmons
MOD
Iain Simmons
Treehouse Moderator 32,305 Points
Iain Simmons
Iain Simmons
Treehouse Moderator 32,305 Points

So, looking at your code, it's actually that the array in the Playlist() constructor function should have the s on the end:

function Playlist() {
  this.songs = [];
  this.nowPlayingIndex = 0;
}

You'll then need to update any time where you're accessing this.song and change it to this.songs.

Also, you're missing the currentSong.play(); from the play method:

Playlist.prototype.play = function() {
  var currentSong = this.songs[this.nowPlayingIndex];
  currentSong.play();
};