JavaScript-DOM nodeValue问题
[英]JavaScript - DOM nodeValue problem
问题描述
Why the function NodeValue__Two() show null ? 
为什么函数NodeValue__Two()显示null ？ To me, it should show the same thing as the function NodeValue__One() . 对我来说，它应该显示与NodeValue__One()函数相同的东西。
I have tested this on IE6. 我已经在IE6上进行了测试。
<html>
<body>
<script language="JavaScript">
function NodeValue__One()
{
alert(myNodeOne.childNodes(0).nodeValue);//This is OK
}
function NodeValue__Two()
{
alert(document.all[6].nodeValue);//This is NOT OK
}
</script>
<p>This PARAGRAPH has two nodes,
<b id="myNodeOne">Node One Text</b>, and
<b id="myNodeTwo">Node Two Text</b>.
<input id="txt1" type="text" value="Damn!!!" />
</p>
<button onclick="NodeValue__One();">Node Value 1</button></br>
<button onclick="NodeValue__Two();">Node Value 2</button>
</body>
</html>
4 个解决方案
解决方案1
3 已采纳 2009-11-13 09:20:49
The All array is an array of Elements. All数组是Elements的数组。 Elements do not have a value in the nodeValue. 元素在nodeValue中没有值。
On the other hand childNodes will contain both Elements and TextNodes. 另一方面， childNodes将同时包含Elements和TextNodes。
Its really hard to get the index of All correct since the number of actual elements listed in All can vary from what you are seeing in the HTML. 很难正确地找到All的索引，因为All列出的实际元素的数量可能与您在HTML中看到的有所不同。 For example dispite there being no HEAD or TITLE Element present in the HTML text, they will be present in the DOM. 例如，尽管HTML文本中没有HEAD或TITLE元素，但它们将出现在DOM中。
解决方案2
2 2009-11-13 09:21:23
Both approaches are deprecated and not safe. 两种方法都已弃用并且不安全。 It would be better if you gave your elements unique identifiers and used getElementById function to find elements in the DOM: 如果为元素提供唯一的标识符，并使用getElementById函数在DOM中查找元素会更好：
var element = document.getElementById('id_of_element');
解决方案3
1 2009-11-13 09:19:50
One reason may be that you have erroneously assumed that "This Paragraph has two nodes". 原因可能是您错误地假定“本段有两个节点”。 It has at least six, including the three text nodes containing "This PARAGRAPH has two nodes,", ", and" and ".". 它至少有六个，包括三个文本节点，其中包含“此PARAGRAPH具有两个节点”，“和”和“。”。
解决方案4
0 2009-11-13 09:26:24
使用document.all[6].text这将为您提供Node Two Text
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