document.getElementById 抛出 TypeError

发布于 2024-11-19 12:00:38 字数 1415 浏览 6 评论 0原文

我对 JavaScript 有点陌生。我正在编写这个虚拟脚本来测试我的较大页面需要什么。我想，最简单的是，获取 href 的值，然后更改 href 的值，然后再次查看它。为了简单起见，现在我删除了更改 href 值的部分，只调用属性值两次。但是当我第二次访问属性值时，它显示一个错误，我在下面发布了该错误。我发布了两份错误日志，一份来自 Firebug，一份来自 Dragonfly（来自 Opera）。

任何帮助将不胜感激。谢谢。

我对脚本的另一个问题是它永远不会完成加载。我总是看到（在 Firefox 3.6.8 中）选项卡标题中转来转去的小加载标志。这并不太困扰我，但如果有人有想法请告诉我。

<!-- This file is used to set attribute value for href. -->
<html>
<head>

<script type="text/javascript">
   function hrefvalue()
{
var thisthang = document.getElementById("1").childNodes[0].getAttribute("href");
document.write(thisthang);
document.write("\n");

var newnew21 = document.getElementById("1").childNodes[0].getAttribute("href");
document.write(newnew21);
}
</script>

</head>

<body>

<div id="1"><a href="focusdude.htm">click here</a></div>
<button type="button" onclick="hrefvalue()">Click me instead</button>

</body>
</html>

错误日志：
1. 萤火虫-> document.getElementById("1") 为 null

2. 蜻蜓->
未捕获的异常：TypeError：无法将 'document.getElementById("1")' 转换为对象

在
中的 hrefvalue() 第 8 行、第 0 列处抛出错误文件://localhost/D:/Chicago%20pics/website%20pics/website%20root/Trial5.htm:
var newnew21 = document.getElementById("1").childNodes[0].getAttribute("href");
从（事件）中的第 1 行第 0 列调用： hrefvalue()

再次感谢所有的鱼：D

原文

I am a bit new to Javascript. I am writing this dummy script to test out what I need for my larger page. I want, at the simplest, to get the value of href and then change the value of href and then see it again. TO keep it simple, right now I have removed the part for changing the href value and just calling the attribute value twice. But the second time I access the attribute value it show an error which I have posted below. I'm posting two error logs one from Firebug and one from Dragonfly(from Opera).

Any help would be dearly appreciated. Thanks.

One more issue I have with the script is that it never finishes loading. I always see (in Firefox 3.6.8) the little loading sign going round and round in the tab title. It doesn't bother me so much but if anyone has an idea please tell me.

<!-- This file is used to set attribute value for href. -->
<html>
<head>

<script type="text/javascript">
   function hrefvalue()
{
var thisthang = document.getElementById("1").childNodes[0].getAttribute("href");
document.write(thisthang);
document.write("\n");

var newnew21 = document.getElementById("1").childNodes[0].getAttribute("href");
document.write(newnew21);
}
</script>

</head>

<body>

<div id="1"><a href="focusdude.htm">click here</a></div>
<button type="button" onclick="hrefvalue()">Click me instead</button>

</body>
</html>

Error logs :
1. Firebug -> document.getElementById("1") is null

2. Dragonfly ->
Uncaught exception: TypeError: Cannot convert 'document.getElementById("1")' to object

Error thrown at line 8, column 0 in hrefvalue() in
file://localhost/D:/Chicago%20pics/website%20pics/website%20root/trial5.htm:
var newnew21 = document.getElementById("1").childNodes[0].getAttribute("href");
called from line 1, column 0 in (event):
hrefvalue()

And thanks again for all the fish :D

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