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Java Java Data Structures - Retired Efficiency! Building the Model

Posted by Javier MARQUEZ
Javier MARQUEZ
11,877 Points

I get Missing.Format.ArgumentExceptions, my code is exactly the same I uderstand everyting I am frustrated and lost :(

Could someone please take a look at my code. I get the below errors.

Adding Exception in thread "main" java.util.MissingFormatArgumentException: Format specifier '%s' at java.util.Formatter.format(Formatter.java:2519)
at java.util.Formatter.format(Formatter.java:2455)
at java.lang.String.format(String.java:2940)
at com.teamtreehouse.model.Song.toString(Song.java:29)
at java.util.Formatter$FormatSpecifier.printString(Formatter.java:2886)
at java.util.Formatter$FormatSpecifier.print(Formatter.java:2763)
at java.util.Formatter.format(Formatter.java:2520)
at java.io.PrintStream.format(PrintStream.java:970)
at java.io.PrintStream.printf(PrintStream.java:871)
at Karaoke.main(Karaoke.java:16)

I had to change the songBook() method, I was being told that I had to declare a retunr value.

Javier MARQUEZ
Javier MARQUEZ
11,877 Points 
import com.teamtreehouse.model.Song;
import com.teamtreehouse.model.SongBook;



public class Karaoke{

  public static void main(String[] args){

    Song song = new Song(     //remember the "new"  in constructors
      "Michael Jackson",
      "Beat it",
      "https://www.youtube.com/watch?v=pvdrN3GJFZo");

    SongBook songBook = new SongBook();
    System.out.printf("Adding %s %n", song);
    songBook.addSong(song);
    System.out.printf("The number of songs is: %d. %n", songBook.getSongCount());



  }



}
Javier MARQUEZ
Javier MARQUEZ
11,877 Points 
package com.teamtreehouse.model;

public class Song{  
  private String mTitle;
  private String mArtist;
  private String mVideoUrl;


  public Song(String artist, String title, String videoUrl){
    mArtist = artist;
    mTitle = title;
    mVideoUrl = videoUrl;    
  }

  public String getTitle(){
    return mTitle;
  }

  public String getArtist(){
    return mArtist;
  }

  public String getVideoUrl(){
    return mVideoUrl;
  }

  @Override
  public String toString(){
    return String.format("Title : %s by %s, click here: %s", mTitle, mArtist);
  }


} ```
Javier MARQUEZ
Javier MARQUEZ
11,877 Points 
 package com.teamtreehouse.model;

import java.util.List; //importing the list interface
import java.util.ArrayList;

public class SongBook{
  private List<Song> mSongs;      //empty interface "mSomething" is private

  public void songBook(){
    mSongs = new ArrayList<Song>(); //remember the "new" word
  }

  public void addSong(Song song){
    mSongs.add(song);
  }

  public int getSongCount(){
    return mSongs.size();
  }

} ```

2 Answers

Simon Coates
Simon Coates
28,694 Points

can you try

return String.format("Title : %s by %s, click here: ", mTitle, mArtist);

think it might be expecting a fourth argument due to three instances of %s

Javier MARQUEZ
Javier MARQUEZ
11,877 Points

And you were right, the string format was waiting for 3 pieces of date. Thanks you so much

Javier MARQUEZ
Javier MARQUEZ
11,877 Points
Javier MARQUEZ
Javier MARQUEZ
11,877 Points

Hello I got it.

I was having an error with the constructor of the Songbook.

I had a typo here: 

public songBook(){
    mSongs = new ArrayList<Song>(); //remember the "new" word
  }

//Constructors have the same name of the class file, CaSeSeNsItIvE!!!

  public SongBook(){
    mSongs = new ArrayList<Song>(); //remember the "new" word
  }