Javascript石头剪刀布小游戏

我正在尝试一个Javascript的石头剪刀游戏。我使用3个图像作为HTML文件中的按钮。我遇到了一个问题的功能，我用它来检查一个胜利。每次我点击一个按钮，我都会得到不同的玩家选择值和电脑选择值，但只有在比较这两个值时，才会得到比较函数中的最后一个值。例如，当我单击“Rock”时，计算机将选择“Paper”-但Javascript将显示我们都选择了“剪刀”（我的比较函数中的最后一个值）。有什么建议吗

/*  SET ALL VARIABLES   */
//set choice variables
var p1Choice;
var p2Choice;
var cChoice;

//set the rock image to act as a button
function rockSelected (p1Choice) {
    p1Choice = "R";
    alert (p1Choice);
}

//set the paper image to act as a button
function paperSelected (p1Choice) {
    p1Choice = "P";
    alert (p1Choice);
}

//set the scissor image to act as a button
function scissorSelected (p1Choice) {
    p1Choice = "S";
    alert (p1Choice);
}

function cpuSelect (cChoice) {
    cChoice = Math.random();
    if (cChoice <= 0.33) {
        cChoice = "R"
        alert (cChoice)}
    else if (cChoice >= 0.34  && cChoice <= 0.66)
    {cChoice = "P";
    alert (cChoice);}
    else 
    {cChoice = "S";
    alert (cChoice);}
}

//check user imput against computer selection
function  compare (p1Choice, cChoice) {
    if (p1Choice == "R") {
        if (cChoice == "R") {
            alert ("player chose rock, cpu chose rock - it was a tie");
            return "it was a tie";
        }
        else if (cChoice == "P") {
            alert ("player chose rock, cpu chose paper - Paper wins!");
            return "paper wins";
        }
        else {
            alert ("player chose rock, cpu chose scissors - rock wins");
            return "rock wins";
        }
    }
    else if (p1Choice == "P") {
        if (cChoice == "R") {
            alert ("player chose paper, cpu chose rock - paper wins");
            return "paper wins";
        } else if (cChoice == "P") {
            alert ("player chose paper, cpu chose paper - it was a tie");
            return "it was a tie";
        } else {
            alert ("player chose paper, cpu chose scissors -scissors wins");
            return "scissors wins";
        }
    }
    else {
        if (cChoice == "R") {
        alert ("player chose scissors, cpu chose rock - rock wins");
        return "rock wins";
        } else if (cChoice == "P") {
            alert ("player chose scissors, cpu chose paper - scissors wins");
            return "scissors wins";
        } else {
            alert ("player chose scissors, cpu chose scissors - it was a tie");
            return "it was a tie";
        }
    }
}

/*设置所有变量*/
//设置选择变量
风险价值选择；
var选择；
变量选择；
//将岩石图像设置为按钮
已选择功能（p1Choice）{
p1Choice=“R”；
警惕（p1选择）；
}
//将纸张图像设置为按钮
已选择功能（p1选项）{
p1Choice=“P”；
警惕（p1选择）；
}
//将剪刀图像设置为按钮
已选择功能剪刀（p1选项）{
p1Choice=“S”；
警惕（p1选择）；
}
功能cpuSelect（选择）{
cChoice=Math.random（）；
如果（cChoice=0.34&&cChoice你可以通过做一个小循环赋值来做一些非常简单的事情：

var choices = {
    rock: {},
    paper: {},
    scissors: {}
};

choices['rock'].beats = choices['scissors'];
choices['paper'].beats = choices['rock'];
choices['scissors'].beats = choices['paper'];

var playerChoice = choices['rock'];
var cpuChoice = choices['paper'];

if(playerChoice.beats === cpuChoice) {
    //winner!
} else if(playerChoice === cpuChoice) {
    //tie
} else {
    //loser
}

问题是，全局变量
p1Choice
和
ccchoice
从未通过
rockSelected
、
paperSelected
、
scissorSelected
和
cpuSelect
方法进行设置。其背后的原因是这些函数定义具有与glob同名的参数所有变量。所以实际发生的是，你只是在改变局部变量的值，这不是你的意图

例如，在
rockSelected
方法中，由于函数定义包括
p1Choice
参数，表达式
p1Choice=“R”
仅设置局部变量，而未定义全局变量

现在，当您调用
compare
方法时，它将始终返回相同的值，因为您的全局变量仍然未定义

要解决此问题，您只需删除
rockSelected
、
paperSelected
、
scissorSelected
、和
cpuSelect
方法的参数。这样就可以设置全局变量，从而使
compare
方法正常工作。例如
rockSelected
方法应如下所示：

function rockSelected() {
    p1Choice = "R";
    alert (p1Choice);
}

您还必须去掉
compare
方法中的两个参数，以便它也使用全局变量

另外，如果您感兴趣，这个bug称为“变量阴影”你可以得到一些关于它的基本信息。基本上，这里要学到的经验是了解变量名的作用域。
我修改了你的代码，以坚持问题的原始目的。问题是你没有使用你创建的函数。我删除了你做的3个函数作为我的mage按钮，因为它们没有引用任何HTML，您也没有提供任何HTML以及未使用的变量。我相信您可以修改代码以提高效率。这是您修改代码的一个工作示例

function cpuSelect () {
    cChoice = Math.random();
    if (cChoice <= 0.33) {
        cChoice = "R";
    alert ("CPU Selected Rock");
    return cChoice;
    }
    else if (cChoice >= 0.34  && cChoice <= 0.66)
    {cChoice = "P";
   alert ("CPU Selected Paper");
    return cChoice;
    }
    else 
    {cChoice = "S";
   alert ("CPU Selected Scissors");
    return cChoice;
    }
}

//check user imput against computer selection
function  compare (p1Choice) {
    cChoice = cpuSelect();

    if (p1Choice == "R") {
        if (cChoice == "R") {
            alert ("player chose rock, cpu chose rock - it was a tie");
            return "it was a tie";
        }
        else if (cChoice == "P") {
            alert ("player chose rock, cpu chose paper - Paper wins!");
            return "paper wins";
        }
        else {
            alert ("player chose rock, cpu chose scissors - rock wins");
            return "rock wins";
        }
    }
    else if (p1Choice == "P") {
        if (cChoice == "R") {
            alert ("player chose paper, cpu chose rock - paper wins");
            return "paper wins";
        } else if (cChoice == "P") {
            alert ("player chose paper, cpu chose paper - it was a tie");
            return "it was a tie";
        } else {
            alert ("player chose paper, cpu chose scissors -scissors wins");
            return "scissors wins";
        }
    }
    else {
        if (cChoice == "R") {
        alert ("player chose scissors, cpu chose rock - rock wins");
        return "rock wins";
        } else if (cChoice == "P") {
            alert ("player chose scissors, cpu chose paper - scissors wins");
            return "scissors wins";
        } else {
            alert ("player chose scissors, cpu chose scissors - it was a tie");
            return "it was a tie";
        }
    }
}

compare("R");

函数cpuSelect（）{
cChoice=Math.random（）；
如果（cChoice=0.34&&cChoice您是否调用过
compare（）
？旁注上的可能重复，则您的代码格式不正确（并且完全不一致）。您应该遵循样式指南，例如，我在HTML文件中的按钮上调用了比较函数。感谢大家的回答。通过删除每个函数传递的参数，我能够使其正常工作。很抱歉，我省略了HTML代码……我正试图简化我的问题。太好了，请确保向上投票l回答并选择一个有帮助的答案。否则，如果这些答案都没有帮助，请添加您自己的答案-这可能会在将来帮助其他人。