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Java Java Data Structures Efficiency! Queueing

Andrea Miotto
.a{fill-rule:evenodd;}techdegree seal-36
Andrea Miotto
iOS Development Techdegree Graduate 23,357 Points

Make a choose before an add

As the title, if you try to make a choose before adding any song, we get and error. This is an exception that we did not manage.

What do u want to do:  choose                                                                                                       
Available artists:                                                                                                                  
Your choice:                                                                                                                        
Exception in thread "main" java.lang.NumberFormatException: For input string: ""                                                    
        at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)                                            
        at java.lang.Integer.parseInt(Integer.java:592)                                                                             
        at java.lang.Integer.parseInt(Integer.java:615)                                                                             
        at com.teamtreehouse.KaraokeMachine.promptForIndex(KaraokeMachine.java:113)                                                 
        at com.teamtreehouse.KaraokeMachine.promptArtist(KaraokeMachine.java:90)                                                    
        at com.teamtreehouse.KaraokeMachine.run(KaraokeMachine.java:59)                                                             
        at Karaoke.main(Karaoke.java:9)              ```

3 Answers

Andrea Miotto
.a{fill-rule:evenodd;}techdegree seal-36
Andrea Miotto
iOS Development Techdegree Graduate 23,357 Points

I just changed KaraokeMachine.java, the run() method:

public void run() {
    String choice = "";
    do {
      try {
        choice = promptAction();
        switch (choice) {
          case "add":
            Song song = promptNewSong();
            System.out.printf("%s added. %n%n", song);
          case "play":
          case "choose":
            //added an if and an else. Probably there is a cleaner way to do it with IOException
            if (mSongBook.getSongCount() != 0) {
              String artist = promptArtist();
              Song artistSong = promptSongForArtist(artist);
              System.out.printf("You chose:  %s %n", artistSong);
            } else {
              System.out.println("\nThere are no songs availabe. Make a new choise \n");
          case "quit":
            System.out.println("Thanks for playing!");
            System.out.printf("Unknow choice: '%s'. Try again. %n%n%n", choice);
      } catch (IOException ioe) {
        System.out.println("Problem with input");
    } while (!choice.equals("quit"));
Iskandar Fendi
Iskandar Fendi
5,700 Points

Can you show me your code in line 65?

Craig Dennis
Craig Dennis
Treehouse Teacher

Good call! Do you have code to fix it?

This should definitely be part of a unit test!