JavaScript 函数无法运行

Question

我被指示制作一个简单的游戏，点击图像会增加你的分数并最终允许升级。当我单击图像时，它会显示第一次剩余的点击量，但是，后续时间似乎不起作用。这是我的函数相互调用方式的问题吗？

Javascript

//Variables
var clicks = 0;
var level = 2;
var clickInterval = 1;
var holdClick = 0;

function imgClicked() { //Activated by clicking on image
    var clicks = clicks + clickInterval; //Increasing clicks
    upgradeCheck();
    if (holdClick === 1) { //If holding down the image activated
        window.onmousedown = holding();
    }
}

function upgradeCheck() { //Check if eligible for new level
    if (clicks > Math.pow(level, 2)) { //If clicks more than current level^2
        level = level + 1; //Next level
        upgrade();

    } else { //If not
        var clicksLeft = Math.pow(level, 2) - clicks; //Determine clicks until eligible
        document.getElementById("toUpgrade").innerHTML = clicksLeft + " clicks left until upgrade"; //Display
    }
}

function upgrade() { //Upgrading
    document.getElementById("clickImg").src = "level" + level + ".png"; //Change to new level
    var clickInterval = clickInterval * 2; //Increase points per click
    if (Math.pow(level, 2) / clickInterval > 400) { //If it take more than 400 clicks to get to next level
        var holdClick = 1; //Activate hold clicking
        document.getElementById("message").innerHTML = "You can now hold down the image";
    }
}

function holding() {
    var clicks = clicks + clickInterval; //Adding more clicks
}

HTML

<p id="toUpgrade"></p>
<img id="clickImg" src="level2.png" onclick="imgClicked()" />
<p> id="message"></p>

Answer 1

我不认为这正在做你认为它正在做的事情:

var clicks = clicks + clickInterval; //Adding more clicks

您没有修改全局 clicks 变量，而是仅在该变量的范围内创建一个名为 clicks 的全新变量功能。然后，当函数完成时，该变量就会消失。您实际上从未修改现有的 clicks 变量。我认为你想要这个:

clicks = clicks + clickInterval; //Adding more clicks

同样的错误在其他地方也犯过，例如:

var clickInterval = clickInterval * 2; //Increase points per click

和:

var holdClick = 1; //Activate hold clicking

删除 var 关键字以防止声明新变量。