Question

Heyo！我正在使用getElementById（）将favicon的href修改为与图片关联的随机数。但是，每次执行此操作时，我尝试将其分配给的变量为null我做错了什么？

<!DOCTYPE html>

<html>
<head>
<script type="text/javascript">


    var number = Math.floor((Math.random() * 5) + 1);

    var ico = number + ".ico"

    document.getElementById("favicon").href = ico <!-- should change the icon -->

</script>
<title>Cool Server People!</title>
<link rel="stylesheet" href="style.css">
<link id="favicon" rel="shortcut icon"  href="1.ico" /> <!-- should edit this part -->

</head>
<body>
<div class="header">
    <h1>Cool Server People</h1>
</div>

<div class="space">

</div>  

<div class="blog">

    <a href="test-post.html" class="post">Blog Post</a>
    <p>asdfdasdfasdfasdfa</p>

</div>

Answer 1

请将您的JS代码放在
此错误是因为您尝试获取早于DOM内容已加载的元素。就是这样！

<!DOCTYPE html>

<html>
<head>
    <title>Cool Server People!</title>
    <link rel="stylesheet" href="style.css">
    <link id="favicon" rel="shortcut icon"  href="1.ico" /> <!-- should edit this part -->

</head>
<body>
<div class="header">
    <h1>Cool Server People</h1>
</div>

<div class="space">

</div>

<div class="blog">

    <a href="test-post.html" class="post">Blog Post</a>
    <p>asdfdasdfasdfasdfa</p>

    <script type="text/javascript">
        
        var number = Math.floor((Math.random() * 5) + 1);
        var ico = number + ".ico";
        document.getElementById("favicon").href = ico; <!-- should change the icon -->

    </script>

</div>

为什么我的变量显示为null？

1 个答案: