Function

Function

• AllUltima1

  what are the controls making up the grid and how are you naming them

  
  
  

• Jody Crozier

  Hi,
  
  Thank you for the information.
  
  It works well.
  
  As a result of your post, I now have learned how to use arrays, and for loops.
  
  Scott
  
  

• nomadicspurs

  In my game, I am using 9 buttons. When the buttons are clicked, they show an X label or a Y label, depending on which was clicked last. The buttons are labelled A1, A2, A3 etc.

  The grid is:

  A1, B1, C1

  A2, B2, C2

  A3, B3, C3

  I want it to check if there are three of the same characters in a row... a win.

  But I want to check after every click, by calling a function.

  
  

• JosW

  Scott;

  I hesitate to post this code, because any "real" developer could probably tell you a thousand more elegant ways of doing this. I have been bailed out several times on this site though, so I am willing to risk the riducule to gain back some karma. In my defense, I tried to use a straight forward approach to clearly show how you might use a function to do what your asking.

  You will notice, that the first thing that I do in the forms Load event, is to put all of your buttons into an array. This allows me to pass only an array to the function, instead of passing each button as a function parameter. Also, I cheated and used one button.click event to handle the button click for all of my TicTacToe buttons. You can choose to keep them seperate if you find it easier.

  Each time that I have a button click, I call the function "isWinner", passing to it the array of buttons and getting from it a true or false based on whether a winner exists. You may have picked up on the fact that I didn't really have to pass the mybuttons array, because it is scoped to the entire class (it can be seen anywhere within the forms code). I passed it anyway to show an example of passing a parameter to a function.

  The code works, except that I didn't check for a winner in the diagonal nor did I include a way to restart the game if nobody wins.

  I hope that this answers your question. If not, at least I have myself a neat little TicTacToe gane now :).

  SteveJ

  Public Class Form1

  Dim mybuttons(8) As Button

  Dim whoseTurn As String = "X"

  ' Event occurrs when form loads - upon program startup

  Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

  ' Put all of the buttons into an array

  mybuttons(0) = Button1

  mybuttons(1) = Button2

  mybuttons(2) = Button3

  mybuttons(3) = Button4

  mybuttons(4) = Button5

  mybuttons(5) = Button6

  mybuttons(6) = Button7

  mybuttons(7) = Button8

  mybuttons(8) = Button9

  ' !!! CALLS A SUBROUTINE, DEFINED BELOW, TO CLEAR ALL BUTTONS !!!

  Me.clearButtons(mybuttons)

  End Sub

  ' THIS EVENT TRIGGERS WHENEVER ONE OF YOUR BUTTONS IS PRESSED

  Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles _

  Button1.Click, Button2.Click, Button3.Click, Button4.Click, Button5.Click, Button6.Click, _

  Button7.Click, Button8.Click, Button9.Click

  Dim _button As Button

  _button = CType(sender, Button)

  ' Don't allow player to write-over an already used button

  If _button.Text = "" Then

  _button.Text = whoseTurn

  ' !!!! CALL THE FUNCTION HERE !!!!

  ' It is getting passed the array, my buttons,

  ' It returns a true or false, based on whether

  ' a winner exists.

  If isWinner(mybuttons) = True Then

  MsgBox("We have a winner: " & whoseTurn)

  ' !!! CALL SUBROUTINE TO CLEAR THE BUTTONS FOR THE NEXT GAME

  Me.clearButtons(mybuttons)

  End If

  If whoseTurn = "X" Then

  whoseTurn = "O"

  Else

  whoseTurn = "X"

  End If

  End If

  End Sub

  ' !!! FUNCTION DECLARATION - CHECK FOR WINNER !!!

  ' Function takes the array of buttons as an argument, and returns

  ' a true/false

  Private Function isWinner(ByVal buttons As Button()) As Boolean

  Dim i As Integer

  Dim _winner As Boolean = False

  For i = 0 To 2

  ' Check for vertical winner

  If buttons(i).Text = buttons(i + 3).Text And buttons(i).Text = buttons(i + 6).Text And _

  Not buttons(i).Text = "" Then

  _winner = True

  End If

  ' Check for horizontal winner

  If buttons(3 * i).Text = buttons(3 * i + 1).Text And buttons(3 * i).Text = buttons(3 * i + 2).Text And _

  Not buttons(3 * i).Text = "" Then

  _winner = True

  End If

  Next

  ' Add code to check for diagonal winner

  Return _winner

  End Function

  ' SUBROUTINE - CLEARS BUTTONS

  Private Sub clearButtons(ByVal buttons As Button())

  Dim _button As Button

  ' Make certain that the text for each button is empty

  For Each _button In mybuttons

  _button.Text = ""

  Next

  End Sub

  End Class

  
  
  
• Function