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Java Java Objects Creating the MVP Scrabble Tiles

Andrei Oprescu
Andrei Oprescu
9,547 Points

Can you help me with this question?

Can you help me with what variable I should use? As I am going through the 'java' objects course I have been given this question:

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 understand What I am supposed to do but I don't know what variables I should use. Currently I have this code:

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) { boolean hasTiles = tile.IndexOf(tile) != -1; return false; }

} I am working on the line 19 ( It sais "boolean hasTiles = tile.IndexOf(tile) != -1;")

do you think you could help and report any mistakes please?

Andrei.

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
    return false;
  }

}

4 Answers

Tornike Shelia
Tornike Shelia
2,781 Points

return tiles.indexOf(tile)>=0;

This is the solution, this will return index number of tile in the tiles , if tile is in tiles then index number will be greater than or equal 0 and this statement will return true, If tile is NOT in the tiles the index number will be -1 and the statement will return false because -1 is not greater than or equal to 0 . Hope this cleares it up , if you have any question feel free to ask .

This statement goes inside the hasTile method.

By the way, you can achieve the goal with many different ways, for example you can use if statement to determine IF the tile is in the tiles and then return true if it is , like this :

if(tiles.indexOf(tile)>=0){
  return true;
}
return false;

This will return true if tile is in tiles and return false if it is NOT . But , our teacher asks us to "practice returning the result of the expression that uses the index of a char in a String." , So thats why I used the different solution.

Andrei Oprescu
Andrei Oprescu
9,547 Points

Hi again,

Am I supposed to use a new string that I should make? At the top of the code It says : // A String representing all of the tiles that this player has

Does that mean I should make a new String?

Andrei

Tornike Shelia
Tornike Shelia
2,781 Points

Hi Andrei , no the comment which teacher left for us is just saying that :

private String tiles;

this is the string which represents all of the tiles that the player has.

Tornike Shelia
Tornike Shelia
2,781 Points

No problem , If my answer helped you to solve the problem and uderstand it , I would appreciate it if you would mark it with green tick :)

I finally figured it out.

public boolean hasTile(char tile) {

boolean isHit = tiles.indexOf(tile) != -1; 

return isHit;

}