► Beginner Java Programming - Episode 3: Tic Tac Toe

In this episode we create the game Tic Tac Toe. We utilize all of the tricks we learned in the Java tutorial on Arrays & For Loops and cover Methods and return types.

[TerraConn]

i have been looking for java coding lessons on youtube for ages and you are my answer!! thank you and keep doing what you are doing!

[kimberlybaker]

You saved my sanity with this video! Thank you so much!  I am now a subscriber and more than likely a daily viewer of your posts.

[CrossCoastGaming]

for the support, within 1 or 2 more videos we will be starting a longer multi-video project that has a graphical component. My plan for that project is to split it up into smaller segments so that there is less code to digest at once, allowing more detailed definitions for each thing we do.  

As for making your own stuff my goal for these first videos is just to expose people to all of the basic tools like loops, if statements, variables, etc. that they can then use or modify to make their own programs.

[bacanalienigena]

Nice job and the logic is very well sorted. Congratulations

[bojiajie]

great videos! I will definitely continue with this series! very gratifying and clearly explained! Thanks.

[eloverphx]

I am liking these videos. My only comment would be to have a downloadable text file with the final product so we can compare our code when we have problems. I am having trouble with my code terminating without a chance to play and I have watched the video multiple times trying to compare my code with your. Thanks again for the education!

[DuskDesertdude]

Hooray! I've been waiting for this!

[AMPnGUITAR]

I'm not sure if anyone has said this yet, but seeing how you posted this a year ago I'm sure you've figured this out.  The easiest way to turn on line numbers is right click in the highlighted space (right to the left of your numbers..) and select "Show Line Numbers"! :) Much much easier and quicker than going through nav stuff. 

[harshchaudhari]

How do you print the condition "GAME OVER! IT IS A TIE " ?

[GMan]

Great video man. Thanks for the upload!

[geoffplays]

The game over Boolean is really confusing, can someone explain how it works?

[Zeptil]

Thank you so much! Saved me on my CS semester project

[CrossCoastGaming]

InfernityArchfiend11 You just need to remove the semicolon before the brackets for your "for statements". :)  Let me know if this helped.

[beg]

So how would you write a condition that states if the player chooses a column or row outside of the predetermined range to "Please choose row and column between 1 and 3"?

[kelleno]

Sup man I realise I am quite late. Just wanted to ask you why in your for loops you aren't using i <= to whatever it is??

[KiDMiO]

i didn't get the rmove, cmove thing...why boolean is based on these and then you set the game over on the if/playing on row and col?

[jimmytrollensky]

if you really study through the code and read each method in order... this really is not too hard of a concept. Great tutorial and the code itself was clever as well. I just started learning from your videos but I did this as well as adding my own features to it :D I cannot figure out however how to stop people from entering things that are not integers... Here is my code:
package ubtuub;

import java.util.Scanner;

public class Main{
public static int row, col;
public static Scanner scan = new Scanner(System.in);
public static char[][] board = new char[3][3];
public static char turn = 'X';

public static void main(String[] args){
for(int i = 0; i < 3; i++){
for (int j = 0; j < 3; j++){
board[i][j] = '_';
}
}
PrintBoard();
Play();
}

public static void Play(){
boolean playing = true;
while(playing){
System.out.println("Please enter a row 1-3 and press enter, followed by a column 1-3 and enter.");
row = scan.nextInt() - 1;
col = scan.nextInt() - 1;
while(validMove(row, col) == false){
System.out.println("Try again.");
PrintBoard();
row = scan.nextInt() - 1;
col = scan.nextInt() - 1;
}
board[row][col] = turn;

if(GameOver(row, col)){
playing = false;
System.out.print("Game over! Player " + turn + " has won!");
}else if(GameDrew()){
playing = false;
System.out.println("Game has ended in a draw!");

Play();
}else{
PrintBoard();
if(turn == 'X'){
turn = 'O';
}else{
turn = 'X';
}
}
}
}

public static void PrintBoard(){
System.out.print(" "+1+" "+2+" "+3);
for(int i = 0; i < 3; i++){
System.out.println();
for (int j = 0; j < 3; j++){
if(j == 0)System.out.print(i + 1 +" | ");
System.out.print(board[i][j] + " | ");
}
}
System.out.println();
}

public static boolean GameOver(int rMove, int cMove){
// Check straight victory
if(board[0][cMove] == board[1][cMove] && board[0][cMove] == board[2][cMove])return true;

if(board[rMove][0] == board[rMove][1] && board[rMove][0] == board[rMove][2]) return true;

// Check diagonal victory
if(board[0][0] == board[1][1] && board[0][0] == board[2][2] && board[1][1] != '_') return true;

if(board[0][2] == board[1][1] && board[0][2] == board[2][0] && board[1][1] != '_') return true;



return false;
}

public static boolean validMove(int rMove, int cMove){
if(rMove > 2 || rMove < 0 || cMove > 2 || cMove < 0){
System.out.println("Invalid space.");
return false;
}else if(board[rMove][cMove] != '_'){
System.out.println("Space taken.");
return false;
}

return true;
}
public static boolean GameDrew(){
int blanks = 0;
for(int i = 0; i < 3; i++){
for(int j = 0; j < 3; j++){
if(board[i][j] != '_'){
blanks++;
}
}
}
if(blanks == 9){
for(int i = 0; i < 3; i++){
for(int j = 0; j < 3; j++){
board[i][j] = '_';
}
}
return true;
}
blanks = 0;
return false;
}

}

[johanabrahamsen]

How can I make the rows have number instead? For example from 1-9 ?

[kiexen]

What if the spots have been taken or the game is on a tie?

[kkm]

the program works, but how do i save it such that it can be seen as a java application? n such that it can be fed into phones & actually be played?