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Code for teaching

Posted by daniel on December 15, 2004 at 9:49 AM EST

What care should be taken with the code we give our students

A student emailed me a link to where the following code was posted for their class. Note: I am not soliciting for other examples of code like this. 



public class Team
{
  private int teamSize = 0;
  private BallPlayer player1, player2, player3, player4, player5,  player6, player7, player8, player9;

  public void getPlayer()
  {

    teamSize++;
    
    switch(teamSize)        
      case 1: player1 = new BallPlayer("first baseman"); 
              System.out.println(player1.getPosition() + " added to team");
              break;
      case 2: player2 = new BallPlayer("pitcher");
              System.out.println(player2.getPosition() + " added to team");
              break;
      case 3: player3 = new BallPlayer("catcher");
              System.out.println(player3.getPosition() + " added to team");
              break;
      case 4: player4 = new BallPlayer("left fielder");
              System.out.println(player4.getPosition() + " added to team");
              break;
      case 5: player5 = new BallPlayer("right fielder");
              System.out.println(player5.getPosition() + " added to team");
              break;
      case 6: player6 = new BallPlayer("shortstop");
              System.out.println(player6.getPosition() + " added to team");
              break;
      case 7: player7 = new BallPlayer("third baseman"); 
              System.out.println(player7.getPosition() + " added to team");
              break;
      case 8: player8 = new BallPlayer("Centerfielder"); 
              System.out.println(player8.getPosition() + " added to team");
              break;
      case 9: player9 = new BallPlayer("second baseman");
              System.out.println(player9.getPosition() + " added to team");
              break;
      }
  }
    
  public int getNumberPlayers()
  {
      return teamSize;
  }
}

The students were asked to clean up code in a class titled BallPlayer and one titled TeamUser, but the proper usage of Team is to call getPlayer nine times. This is code intended to teach students the switch statement in their first course in Java. I'm scratching my head over much of it starting with the void return type for getPlayer() and the use of switch in the first place for this example.

As a child I hated hearing adults say "do what I say and not what I do." As a teacher, I often fall short but I do aim to model the behavior I'm trying to teach. If I want the students to write test-first then I better do the same when possible. I know there's lots of bad code out there, but this class struck me.

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What care should be taken with the code we give our students
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