index.js

const cells = document.querySelectorAll(".cell");
const statusText = document.querySelector("#statusText");
const restartBtn = document.querySelector("#restartBtn");
const winConditions = [
    [0, 1, 2],
    [3, 4, 5],
    [6, 7, 8],
    [0, 3, 6],
    [1, 4, 7],
    [2, 5, 8],
    [0, 4, 8],
    [2, 4, 6]
];
let options = ["","","","","","","","",""];
let currentPlayer = "X";
let running = false;

initializeGame();

function initializeGame(){
    cells.forEach(cell => cell.addEventListener("click", cellClicked));
    restartBtn.addEventListener("click", restartGame);
    statusText.textContent = `${currentPlayer}'s turn`;
    running = true;
}
function cellClicked() {
    const cellIndex = this.getAttribute("cellIndex");
    if(options[cellIndex] != "" || !running) {
        return;
    }

    updateCell(this, cellIndex);
    checkWinner();
}
function updateCell(cell, index) {
    options[index] = currentPlayer;
    cell.textContent = currentPlayer;
};
function changePlayer() {
    currentPlayer = (currentPlayer == "X") ? "O" : "X";
    statusText.textContent = `${currentPlayer}'s turn`;
}
function checkWinner(){
    let roundWon = false;
    for(let i = 0; i < winConditions.length; i++) {
        const condition = winConditions[i];
        const cellA = options[condition[0]];
        const cellB = options[condition[1]];
        const cellC = options[condition[2]];
        
        if(cellA == "" || cellB == "" || cellC == ""){
            continue;
        }
        if(cellA == cellB && cellB == cellC){
            roundWon = true;
            break;
        }
    }
    if(roundWon){
        statusText.textContent = `${currentPlayer} wins!`
        running = false;
    } else if (!options.includes("")){
        statusText.textContent = `Draw!`
        running = false;
    } else {
        changePlayer();
    }
    
}
function restartGame() {
    currentPlayer = 'X';
    options = ["","","","","","","","",""];
    statusText.textContent = `${currentPlayer}'s turn`;
    cells.forEach(cell => cell.textContent = "");
    running = true;
}