将多个函数添加到外部javascript文件

Question

我正在努力将javascript功能添加到具有多个按钮的基本HTML页面.当我在外部JS文件中包含一个函数时,代码可以工作,但当我尝试添加另一个按钮功能时,代码停止工作.

我该如何解决这个问题？

HTML:

<!DOCTYPE html>
<html>
<head>
    <title>Jiggle Into JavaScript</title>
    <!-- <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script> -->
</head>
<body>

    <p>Press the buttons to change the box!</p>

    <div id="box" style="height:150px; width:150px; background-color:orange; margin:25px"></div>

    <button id="button1">Grow</button>
    <button id="button2">Blue</button>
    <button id="button3">Fade</button>
    <button id="button4">Reset</button>

    <script type="text/javascript" src="javascript.js"></script>

</body>
</html>

片段:

document.getElementById("button1").addEventListener("click", function(){
  document.getElementById("box").style.height = "500px";
});

document.getElementById("button2").addEventListener("click", function(){
  document.getElementById("box").style.background-color = "blue";
});

<p>Press the buttons to change the box!</p>
<div id="box" style="height:150px; width:150px; background-color:orange; margin:25px"></div>
<button id="button1">Grow</button>
<button id="button2">Blue</button>
<button id="button3">Fade</button>
<button id="button4">Reset</button>

Answer 1

您的语法不正确:

document.getElementById("box").style.background-color = "blue";

-是减法运算符,它不能用作属性文字的一部分.通过将CSS名称转换为camelCase来创建样式属性,因此它应该是:

document.getElementById("box").style.backgroundColor = "blue";