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Java Java Objects Creating the MVP Scrabble Tiles

Posted by roshaan zafar
roshaan zafar
3,868 Points

how to determine if user has pass the tile

cant make right algorithim

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) {
    // TODO: Add the tile to tiles
   this.tiles+="tiles";
  }

  public boolean hasTile(char tile) {
    // TODO: Determine if user has the tile passed in
    boolean hasTile=tiles.indexOf("tiles")==-1;

     return hasTile;


  }

}

2 Answers

Steve Hunter
Steve Hunter
57,712 Points
Steve Hunter
Steve Hunter
57,712 Points

Hi Roshaan,

The first task is to add the parameter to the tiles member variable. The parameter tile is passed into the method. In there you want to use += to add tile onto tiles. You can use this if you like, for greater readability. That looks like:

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

The next part is seeing if tile is in tiles and you are so close!

You've correctly highlighted that you need to test using indexOf() whether that's something to with -1. Totally correct. The indexOf() method will return -1 if tile is not in tiles. That expression would look like:

tiles.indexOf(tile)

That will evaluate to -1 if tile isn't in tiles. So, if we compare that to -1, checking for equality, we get a true/false answer. Like this:

tiles.indexOf(tiles) == -1

That evaluates to true if the result of the expression is -1. That's not what we want. The instructions want that scenario to return false. So, let's just negate the test. Rather than seeing if the expression == -1 let's see if it doesn't equal -1 - that's using !=. The not-equal-to operator. That becomes tiles.indexOf(tile) != -1

So now we have an expression that evaluates to true or false, as required. We just need to return that from the method, right? How about:

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

I hope that makes sense.

Steve.

roshaan zafar
roshaan zafar
3,868 Points
roshaan zafar
roshaan zafar
3,868 Points

thanks steve