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Java Java Objects Creating the MVP Scrabble Tiles

Kaytlynn Ransom
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Kaytlynn Ransom
Python Web Development Techdegree Student 11,409 Points
Posted by Kaytlynn Ransom
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Kaytlynn Ransom
Python Web Development Techdegree Student 11,409 Points

Why can't I use an if statement?

The exact question for the exercise is stated like this:

Correct the existing hasTile method to return true if the tile is in the tiles field, and false if it isn't. You can solve this a few ways, however, I'd like you to practice returning the result of the expression that uses the index of a char in a String.

I'm confused mostly by the last sentence. It tells me that it wants me to return true or false, but then it tells me that I need to return the expression using the index of a char in a String. How can I reconcile these two requirements to answer the problem correctly?

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;

  }

  public boolean hasTile(char tile) {
    // TODO: Determine if user has the tile passed in
    boolean passedIn = tiles.indexOf(tile) != -1;
    if (passedIn) {
      return passedIn;
  } else {
      return false;
  }
  }
}

1 Answer

Richard Lambert
PLUS
Richard Lambert
Courses Plus Student 7,180 Points
Richard Lambert
Richard Lambert
Courses Plus Student 7,180 Points

Hello mate,

You can use an if-else statement:

public boolean hasTile(char tile) {
    boolean isPassedIn = tiles.indexOf(tile) != -1;
    if (isPassedIn) {
        return true;
    } else {
        return false;
    }
}

The following code also offers the same logic:

public boolean hasTile(char tile) {
    return tiles.indexOf(tile) != -1;
}

As you can see, creating an if-else statement introduces a lot of redundant code, but that doesn't make it incorrect. As to which implementation the Treehouse Java test engine will accept, I've tested the second and it passes; both make use of String's .indexOf(char c) method and return a boolean based on the presence or lack of a character in a given string, so should pass.

Hope this helps

Richard Lambert
Richard Lambert
Courses Plus Student 7,180 Points
Richard Lambert
Richard Lambert
Courses Plus Student 7,180 Points

UPDATE: Just tried this using an if-else statement and received "Bummer! While you could definitely solve this using an if statement, try returning the result of the expression." A case of the Treehouse Java test engine expecting a specific implementation.