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Java Java Objects Creating the MVP Scrabble Tiles

Jimmy Seeber
Jimmy Seeber
12,809 Points
Posted by Jimmy Seeber
Jimmy Seeber
12,809 Points

Please explain why my solution is marked incorrect. if(tiles.indexOf(tile) == -1) return false; return true;

The equivalent is also:

if(tiles.indexOf(tile) == -1){
  return false;
}else{ 
  return true;
}

which is also marked incorrect.

ScrabblePlayer.java 
public class ScrabblePlayer {
  // A String representing all of the tiles that this player has
  private String tiles;

  public ScrabblePlayer() {
    tiles = "";
  }

  public String getTiles() {
    return tiles;
  }

  public void addTile(char tile) {
    tiles += tile;
    // TODO: Add the tile to tiles

  }

  public boolean hasTile(char tile) {
    // TODO: Determine if user has the tile passed in

    if(tiles.indexOf(tile) == -1){
      return false;
    }else{
      return true;
    }
  }

}

1 Answer

Abu Muhariba
Abu Muhariba
1,140 Points
Abu Muhariba
Abu Muhariba
1,140 Points 
public boolean hasTile(char tile) {
    // TODO: Determine if user has the tile passed in

    if(tiles.indexOf(tile) == -1){
      return false;
    }else{
      return true;
    }

The expression tiles.indexOf(tile) == -1 is a boolean expression. Therefore it returns a true or false statement. This means the if statement is redundant and we can simply return (tiles.indexOf(tile) == -1); i.e. return a true or false

The -1 also needs to be changed to a 1 as -1 indicates the tile is not present in tiles.

Your solution is correct per se but that's not what this specific exercises is looking for. Thus if you were to run the exact code above Team Treehouse would state: While you could definitely solve this using an if statement, try returning the result of the expression.

[MOD: edited code block & changed comment to answer - srh]

Steve Hunter
Steve Hunter
57,712 Points

I think you can test whether tiles.indexOf(tile) is either not -1 or is zero or more. That's the same test.

You don't want to use the index of 1 as the indices are zero-based. The indexOf method returns the position in the string, or -1 if the character isn't present. If tile is the first character in tiles, it'll return zero. You are correct that the result of this expression just needs returning. Redundant tests are easy to add!

So, there's two tests that should work here:

return tiles.indexOf(tile) != -1;

// or

return tiles.indexOf(tile) >= 0;

I hope that helps.

Steve.