not able to understand the compiler error

 public class ScrabblePlayer {
  private String mHand;

  public ScrabblePlayer() {
    mHand = "";
  }

  public String getHand() {
   return mHand;
  }

  public void addTile(char tile) {
    // Adds the tile to the hand of the player
    mHand += tile;
  }

  public boolean hasTile(char tile) {
   return mHand.indexOf(tile) > -1;
  }

  public int getTileCount(char tile) {
    int counter = 0;
    for (char letter: mHand.toCharArray()) {
      if(letter == tile) {
            counter += 1;
        }
    }
   return counter;
  }  
 public int getCountOfLetter(char tiles){
 int count= 0;
     for(char letter : mHand.toCharArray()){

     if(letter == tile){
     count+=1;

     }
}
     return count;
}
}

// This code is here for example purposes only
public class Example {

  public static void main(String[] args) {
    ScrabblePlayer player1 = new ScrabblePlayer();
    player1.addTile('d');
    player1.addTile('d');
    player1.addTile('p');
    player1.addTile('e');
    player1.addTile('l');
    player1.addTile('u');

    ScrabblePlayer player2 = new ScrabblePlayer();
    player2.addTile('z');
    player2.addTile('z');
    player2.addTile('y');
    player2.addTile('f');
    player2.addTile('u');
    player2.addTile('z');

    int count = 0;
    // This would set count to 1 because player1 has 1 'p' tile in her collection of tiles
    count = player1.getCountOfLetter('p');
    // This would set count to 2 because player1 has 2 'd'' tiles in her collection of tiles
    count = player1.getCountOfLetter('d');
    // This would set 0, because there isn't an 'a' tile in player1's tiles
    count = player1.getCountOfLetter('a');

    // This will return 3 because player2 has 3 'z' tiles in his collection of tiles
    count = player2.getCountOfLetter('z');
    // This will return 1 because player2 has 1 'f' tiles in his collection of tiles
    count = player2.getCountOfLetter('f');
  }
}