javascript - 石头剪刀布 Javascript 函数

Question

我现在有我的石头剪刀布 JS 游戏的代码。在我的比较功能中，我尝试对其进行编程，以便在未输入“Rock”、“Paper”或“Scissors”时显示警告消息。但是它不起作用，当我输入与有效的 3 个选项不同的字符串时，我没有得到任何响应。

var userChoice = prompt("Rock, Paper, or Scissors");
var computerChoice = Math.random();

var compchoice = function ()
{
    if (computerChoice <= 0.34)
    {
        return computerChoice = "Rock";
    } 
    else if(computerChoice <= 0.67 && computerChoice >= 0.35)
    {
        return computerChoice = "Paper";
    }
    if (computerChoice >= 0.68)
    {
        return computerChoice = "Scissors";
    }

};

var compare = function (choice1, choice2)
{
    if (computerChoice === "Rock" || "Paper" || "Scissors")
    {
        if (choice1 === choice2)
        {
            return alert("The result is a tie!");
        }

        else if (choice1 === "Rock")
        {
            if (choice2 === "Scissors")
            {
                return alert("Rock crushes Scissors!");
            }
            else if (choice2 === "Paper")
            {
                return alert("Paper covers Rock!");
            }
        }
        if (choice1 === "Scissors")
        {
            if (choice2 === "Rock")
            {
                return alert("Rock crushes Scissors!");
            }
            else if (choice2 === "Paper")
            {
                return alert("Scissors cuts Paper!");
            }
        }
        else if (choice1 === "Paper")
        {
            if (choice2 === "Rock")
            {
                return alert("Paper covers Rock!");
            }
            else if (choice2 === "Scissors")
            {
                return alert("Scissors cuts Paper!");
            }
        }
    }
    else 
    {
        return alert("Please type Rock, Paper, or Scissors next           time");
    }
};

compchoice();

compare(userChoice, computerChoice);

有什么原因吗？

Answer 1

computerChoice === "摇滚"|| “纸” || “剪刀” 始终为真，因为它解析为:

(computerChoice === "Rock") || ("Paper") || ("Scissors")

"Paper" 是一个真值。

此外，您似乎在比较 computerChoice，而不是 userChoice。

固定:

if (userChoice === "Rock" || userChoice === "Paper" || userChoice === "Scissors")

或者:

// array and indexOf
if (["Rock", "Paper", "Scissors"].indexOf(userChoice) > -1)
// doesn't work in IE8

或者:

// regex
if (/^(Rock|Paper|Scissors)$/.test(userChoice))