是一种将变量添加到自身
的方法document.getElementById("demo").innerHTML = deck;
document.getElementById("player1").innerHTML = deck[0];
document.getElementById("player2").innerHTML = deck[1];
document.getElementById("pc1").innerHTML = deck[2];
document.getElementById("pc2").innerHTML = deck[3];
<p id="demo"></p>
var score = score + deck[0] + deck[1];
document.getElementById("demo").innerHTML = score;
}