script.js

let isPlayerOne = true;
let cells = document.getElementsByClassName("cell");

for (let i = 0; i < cells.length; i++) {
    cells[i].addEventListener('click', userMove);
}

document.getElementById('resetButton').addEventListener('click', resetGame);

function userMove(e) {
    let cellValue = e.target.innerHTML;
    if (!cellValue.length) {
        e.target.innerHTML = isPlayerOne ? 'X' : 'O';
        isPlayerOne = !isPlayerOne;

        checkline(0, 1, 2);
        checkline(3, 4, 5);
        checkline(6, 7, 8);
        checkline(0, 3, 6);
        checkline(1, 4, 7);
        checkline(2, 5, 8);
        checkline(0, 4, 8);
        checkline(6, 4, 2);
    }
}

function checkline(c1, c2, c3) {
    if (
        cells[c1].innerHTML.length &&
        cells[c1].innerHTML == cells[c2].innerHTML &&
        cells[c2].innerHTML == cells[c3].innerHTML
    ) {
        showWinner(cells[c1].innerHTML);
    }
}

function showWinner(player) {
    document.querySelector('#results h2').innerHTML = "El ganador es la " + player;
}

function resetGame() {
    for (let i = 0; i < cells.length; i++) {
        cells[i].innerHTML = '';  
    }
    isPlayerOne = true; 
    document.querySelector('#results h2').innerHTML = ''; 
}