getElementById()
Function: Find the element object with the specified id in the web page.
Syntax: var obj = document.getElementById(id)
Parameters: id refers to the value of the id attribute marked in the web page.
Return value: Returns an element object.
Example: var imgObj = document.getElementById(“img01”)
getElementsByTagName(tagName)
- ##Function: Find the specified HTML tag and return an array.
- Syntax: var arrObj = parentNode.getElementsByTagName(tagName)
- Parameters: tagName is the tag name to be found, without angle brackets.
- Return value: Returns an array. If there is only one node, an array is also returned.
- Example: var arrObj = ulObj.getElementsByTagName(“li”)
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>php.cn</title>
<script type="text/javascript">
window.onload = function(){
//获取id=ulTag的网页对象
var ulObj = document.getElementById("question");
//查找<ul>下的所有的<li>标记
var arrObj = ulObj.getElementsByTagName("li");
//给所有的<li>标记增加CSS效果
for(var i=0;i<arrObj.length;i++)
{
//给每个<li>标记加style属性
arrObj[i].style = "color:blue;font-size:24px;";
}
}
</script>
</head>
<body >
<ul id="question">
<li>mac 中系统自带的apache 误删了怎么恢复</li>
<li>CURL POST数据量过大，接收不到服务端的信息</li>
<li>用了构造函数为什么这个还是2？</li>
<li>cookies登录原理</li>
</ul>
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