MemoryGame.js

const emojis = ["🍫", "🍫", "🍭", "🍭", "🎂", "🎂", "🍺", "🍺", "🍗",
    "🍗", "🍟", "🍟", "🍔", "🍔", "🍕", "🍕"];
var shuf_emojis = emojis.sort(() => (Math.random() > .5) ? 2 : -1);
for (var i = 0; i < emojis.length; i++) {
    let box = document.createElement('div');
    box.className = 'item';
    box.innerHTML = shuf_emojis[i];

    box.onclick = function () {
        this.classList.add('boxOpen');
        setTimeout(function () {
            if (document.querySelectorAll('.boxOpen').length > 1) {
                if (document.querySelectorAll('.boxOpen')[0].innerHTML ==
                    document.querySelectorAll('.boxOpen')[1].innerHTML) {
                    document.querySelectorAll('.boxOpen')[0].classList.add('boxMatch')
                    document.querySelectorAll('.boxOpen')[1].classList.add('boxMatch')

                    document.querySelectorAll('.boxOpen')[1].classList.remove('boxOpen')
                    document.querySelectorAll('.boxOpen')[0].classList.remove('boxOpen')

                    if (document.querySelectorAll('.boxMatch').length == emojis.length) {
                        document.querySelector("h2").classList.add('win')
                        document.querySelector("h2").innerHTML = "YOU WIN !!"
                    }
                } else {
                    document.querySelectorAll('.boxOpen')[1].classList.remove('boxOpen')
                    document.querySelectorAll('.boxOpen')[0].classList.remove('boxOpen')
                }
            }
        }, 500)
    }
    document.querySelector('.game').appendChild(box);
}