Tic Tac Toe game in PHP

How to Play Tic Tac Toe Game

Input the game participant/contestant/players names to play and click start.
The software will show the game participant/contestant/players’ names for each participant/contestant/player’s turn. The participant/contestant/player’s move will be submitted by pressing the Play Button on the interface.
The first participant/contestant/player to align their marks horizontally, vertically, or diagonally will be the champion of the game.

Functional requirements of Tic Tac Toe Game

The game Participant/contestant/players Choosing Side Form/Module

Game Module
The participant/contestant/players Score Board Module

participant contestant Screenshot of output is given below for your general understandings.

Tic Tac Toe Game using PHP

index.php

<?php
require_once "./templates/header.php";
?>

<form method="post" action="register-players.php">
    <div class="welcome">
        <h1>Start playing Tic Tac Toe!</h1>
        <h2>Please fill in your names</h2>

        <div class="p-name">
            <label for="player-x"> Player (First)</label>
            <input type="text" id="player-x" name="player-x" required />
        </div>

        <div class="p-name">
            <label for="player-o"> Player (Sceond)</label>
            <input type="text" id="player-o" name="player-o" required />
        </div>

        <button type="submit">Start</button>
    </div>
</form>

<?php
require_once "./templates/footer.php";

<?php

require_once "./templates/header.php";

<h1>Start playing Tic Tac Toe!</h1>

<h2>Please fill in your names</h2>

<label for="player-x"> Player (First)</label>

</div>

<label for="player-o"> Player (Sceond)</label>

</div>

<button type="submit">Start</button>

</div>

</form>

<?php

require_once "./templates/footer.php";

play.php

<?php
require_once "templates/header.php";

if (! playersRegistered()) {
    header("location: index.php");
}

if ($_POST['cell']) {
    $win = play($_POST['cell']);

    if ($win) {
        header("location: result.php?player=" . getTurn());
    }
}

if (playsCount() >= 9) {
    header("location: result.php");
}
?>

<h2><?php echo currentPlayer() ?>'s turn</h2>

<form method="post" action="play.php">

    <table class="tic-tac-toe" cellpadding="0" cellspacing="0">
        <tbody>

        <?php
        $lastRow = 0;
        for ($i = 1; $i <= 9; $i++) {
            $row = ceil($i / 3);

            if ($row !== $lastRow) {
                $lastRow = $row;

                if ($i > 1) {
                    echo "</tr>";
                }

                echo "<tr class='row-{$row}'>";
            }

            $additionalClass = '';

            if ($i == 2 || $i == 8) {
                $additionalClass = 'vertical-border';
            }
            else if ($i == 4 || $i == 6) {
                $additionalClass = 'horizontal-border';
            }
            else if ($i == 5) {
                $additionalClass = 'center-border';
            }
            ?>

            <td class="cell-<?= $i ?> <?= $additionalClass ?>">
                <?php if (getCell($i) === 'x'): ?>
                    X
                <?php elseif (getCell($i) === 'o'): ?>
                    O
                <?php else: ?>
                    <input type="radio" name="cell" value="<?= $i ?>" onclick="enableButton()"/>
                <?php endif; ?>
            </td>

        <?php } ?>

        </tr>
        </tbody>
    </table>

    <button type="submit" disabled id="play-btn">Play</button>

</form>

<script type="text/javascript">
    function enableButton() {
        document.getElementById('play-btn').disabled = false;
    }
</script>

<?php
require_once "templates/footer.php";

<?php

require_once "templates/header.php";

if (! playersRegistered()) {

header("location: index.php");

}

if ($_POST['cell']) {

$win = play($_POST['cell']);

if ($win) {

header("location: result.php?player=" . getTurn());

}

if (playsCount() >= 9) {

header("location: result.php");

}

<tbody>

<?php

$lastRow = 0;

for ($i = 1; $i <= 9; $i++) {

$row = ceil($i / 3);

if ($row !== $lastRow) {

$lastRow = $row;

if ($i > 1) {

echo "</tr>";

}

echo "<tr class='row-{$row}'>";

}

$additionalClass = '';

if ($i == 2 || $i == 8) {

$additionalClass = 'vertical-border';

}

else if ($i == 4 || $i == 6) {

$additionalClass = 'horizontal-border';

}

else if ($i == 5) {

$additionalClass = 'center-border';

}

<?php if (getCell($i) === 'x'): ?>

<?php elseif (getCell($i) === 'o'): ?>

<?php else: ?>

<input type="radio" name="cell" value="<?= $i ?>" onclick="enableButton()"/>

<?php endif; ?>

</td>

<?php } ?>

</tr>

</tbody>

</table>

</form>

function enableButton() {

document.getElementById('play-btn').disabled = false;

}

</script>

<?php

require_once "templates/footer.php";

register-players.php

<?php

require_once "functions.php";

registerPlayers($_POST['player-x'], $_POST['player-o']);

if (playersRegistered()) {
    header("location: play.php");
}

<?php

require_once "functions.php";

registerPlayers($_POST['player-x'], $_POST['player-o']);

if (playersRegistered()) {

header("location: play.php");

}

result.php

<?php
require_once "templates/header.php";

if (! playersRegistered()) {
    header("location: index.php");
}

resetBoard();
?>

<table class="wrapper" cellpadding="0" cellspacing="0">
    <tr>
        <td>

            <div class="welcome">

                <h1>
                    <?php
                    if ($_GET['player']) {
                        echo currentPlayer() . " won!";
                    }
                    else {
                        echo "It's a tie!";
                    }
                    ?>
                </h1>

                <div class="player-name">
                    <?php echo playerName('x')?>'s score: <b><?php echo score('x')?></b>
                </div>

                <div class="player-name">
                    <?php echo playerName('o')?>' score: <b><?php echo score('o')?></b>
                </div>

                <a href="play.php">Play again</a><br />

                <a href="index.php" class="reset-btn">Reset</a>
            </div>

        </td>
    </tr>
</table>

</body>
</html>

<?php

require_once "templates/header.php";

if (! playersRegistered()) {

header("location: index.php");

}

resetBoard();

<tr>

<td>

<h1>

<?php

if ($_GET['player']) {

echo currentPlayer() . " won!";

}

else {

echo "It's a tie!";

}

</h1>

<?php echo playerName('x')?>'s score: <b><?php echo score('x')?></b>

</div>

<?php echo playerName('o')?>' score: <b><?php echo score('o')?></b>

</div>

<a href="play.php">Play again</a><br />

<a href="index.php" class="reset-btn">Reset</a>

</div>

</td>

</tr>

</table>

</body>

</html>

functions.php

<?php

session_start();
error_reporting(E_ERROR | E_PARSE);

function registerPlayers($playerX="", $playerO="") {
    $_SESSION['PLAYER_X_NAME'] = $playerX;
    $_SESSION['PLAYER_O_NAME'] = $playerO;
    setTurn('x');
    resetBoard();
    resetWins();
}

function resetBoard() {
    resetPlaysCount();

    for ( $i = 1; $i <= 9; $i++ ) {
        unset($_SESSION['CELL_' . $i]);
    }
}

function resetWins() {
    $_SESSION['PLAYER_X_WINS'] = 0;
    $_SESSION['PLAYER_O_WINS'] = 0;
}

function playsCount() {
    return $_SESSION['PLAYS'] ? $_SESSION['PLAYS'] : 0;
}

function addPlaysCount() {
    if (! $_SESSION['PLAYS']) {
        $_SESSION['PLAYS'] = 0;
    }

    $_SESSION['PLAYS']++;
}

function resetPlaysCount() {
    $_SESSION['PLAYS'] = 0;
}

function playerName($player='x') {
    return $_SESSION['PLAYER_' . strtoupper($player) . '_NAME'];

}

function playersRegistered() {
    return $_SESSION['PLAYER_X_NAME'] && $_SESSION['PLAYER_O_NAME'];
}

function setTurn($turn='x') {
    $_SESSION['TURN'] = $turn;
}

function getTurn() {
    return $_SESSION['TURN'] ? $_SESSION['TURN'] : 'x';
}

function markWin($player='x') {
    $_SESSION['PLAYER_' . strtoupper($player) . '_WINS']++;
}

function switchTurn() {
    switch (getTurn()) {
        case 'x':
            setTurn('o');
            break;
        default:
            setTurn('x');
            break;
    }
}

function currentPlayer() {
    return playerName(getTurn());
}

function play($cell='') {
    if (getCell($cell)) {
        return false;
    }

    $_SESSION['CELL_' . $cell] = getTurn();
    addPlaysCount();
    $win = playerPlayWin($cell);

    if (! $win) {
        switchTurn();
    }
    else {
        markWin(getTurn());
        resetBoard();
    }

    return $win;
}

function getCell($cell='') {
    return $_SESSION['CELL_' . $cell];
}

function playerPlayWin($cell=1) {
    if (playsCount() < 3) {
        return false;
    }

    $column = $cell % 3;
    if (! $column) {
        $column = 3;
    }

    $row = ceil($cell / 3);

    $player = getTurn();

    return isVerticalWin($column, $player) || isHorizontalWin($row, $player) || isDiagonalWin($player);
}

function isVerticalWin($column=1, $turn='x') {
    return getCell($column) == $turn &&
        getCell($column + 3) == $turn &&
        getCell($column + 6) == $turn;
}

function isHorizontalWin($row=1, $turn='x') {
    return getCell($row) == $turn &&
        getCell($row + 1) == $turn &&
        getCell($row + 2) == $turn;
}

function isDiagonalWin($turn='x') {
    $win = getCell(1) == $turn &&
        getCell(9) == $turn;

    if (! $win) {
        $win = getCell(3) == $turn &&
            getCell(7) == $turn;
    }

    return $win && getCell(5) == $turn;
}

function score($player='x') {
    $score = $_SESSION['PLAYER_' . strtoupper($player) . '_WINS'];
    return $score ? $score : 0;
}

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<?php

session_start();

error_reporting(E_ERROR | E_PARSE);

function registerPlayers($playerX="", $playerO="") {

$_SESSION['PLAYER_X_NAME'] = $playerX;

$_SESSION['PLAYER_O_NAME'] = $playerO;

setTurn('x');

resetBoard();

resetWins();

}

function resetBoard() {

resetPlaysCount();

for ( $i = 1; $i <= 9; $i++ ) {

unset($_SESSION['CELL_' . $i]);

}

function resetWins() {

$_SESSION['PLAYER_X_WINS'] = 0;

$_SESSION['PLAYER_O_WINS'] = 0;

}

function playsCount() {

return $_SESSION['PLAYS'] ? $_SESSION['PLAYS'] : 0;

}

function addPlaysCount() {

if (! $_SESSION['PLAYS']) {

$_SESSION['PLAYS'] = 0;

}

$_SESSION['PLAYS']++;

}

function resetPlaysCount() {

$_SESSION['PLAYS'] = 0;

}

function playerName($player='x') {

return $_SESSION['PLAYER_' . strtoupper($player) . '_NAME'];

}

function playersRegistered() {

return $_SESSION['PLAYER_X_NAME'] && $_SESSION['PLAYER_O_NAME'];

}

function setTurn($turn='x') {

$_SESSION['TURN'] = $turn;

}

function getTurn() {

return $_SESSION['TURN'] ? $_SESSION['TURN'] : 'x';

}

function markWin($player='x') {

$_SESSION['PLAYER_' . strtoupper($player) . '_WINS']++;

}

function switchTurn() {

switch (getTurn()) {

case 'x':

setTurn('o');

break;

default:

setTurn('x');

break;

}

function currentPlayer() {

return playerName(getTurn());

}

function play($cell='') {

if (getCell($cell)) {

return false;

}

$_SESSION['CELL_' . $cell] = getTurn();

addPlaysCount();

$win = playerPlayWin($cell);

if (! $win) {

switchTurn();

}

else {

markWin(getTurn());

resetBoard();

}

return $win;

}

function getCell($cell='') {

return $_SESSION['CELL_' . $cell];

}

function playerPlayWin($cell=1) {

if (playsCount() < 3) {

return false;

}

$column = $cell % 3;

if (! $column) {

$column = 3;

}

$row = ceil($cell / 3);

$player = getTurn();

return isVerticalWin($column, $player) || isHorizontalWin($row, $player) || isDiagonalWin($player);

}

function isVerticalWin($column=1, $turn='x') {

return getCell($column) == $turn &&

getCell($column + 3) == $turn &&

getCell($column + 6) == $turn;

}

function isHorizontalWin($row=1, $turn='x') {

return getCell($row) == $turn &&

getCell($row + 1) == $turn &&

getCell($row + 2) == $turn;

}

function isDiagonalWin($turn='x') {

$win = getCell(1) == $turn &&

getCell(9) == $turn;

if (! $win) {

$win = getCell(3) == $turn &&

getCell(7) == $turn;

}

return $win && getCell(5) == $turn;

}

function score($player='x') {

$score = $_SESSION['PLAYER_' . strtoupper($player) . '_WINS'];

return $score ? $score : 0;

}

Download Tic Tac Toe game in PHP

Tic Tac Toe game in PHP
By: Prof. Dr. Fazal Rehman | Last updated: March 16, 2022