Are there any best practices or design patterns that can be applied to improve the structure and functionality of a PHP-based Tic Tac Toe game?

One way to improve the structure and functionality of a PHP-based Tic Tac Toe game is to use the MVC (Model-View-Controller) design pattern. This helps separate the game logic (Model), user interface (View), and user input handling (Controller) which makes the code more organized and easier to maintain.

// Model (game logic)
class TicTacToe {
    // Game logic methods here
}

// View (user interface)
class TicTacToeView {
    // User interface methods here
}

// Controller (user input handling)
class TicTacToeController {
    // User input handling methods here
}

// Usage example
$model = new TicTacToe();
$view = new TicTacToeView();
$controller = new TicTacToeController($model, $view);