getElementById,getElementsByName,getElementsByTagName的使用和区别 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<script type="text/javascript">
function getValue(){
    var x=document.getElementById("myHeader");
    alert(x.innerHTML);
}
function getElements(){
    var x=document.getElementsByName("myInput");
    alert(x.length);
}
function getElementsByTagNames(){
    var x=document.getElementsByTagName("input");
    alert(x.length);
}
</script>
</head>

<body>
<h1 id="myHeader" onclick="getValue()">this title</h1>
<p>click title,will show its value</p>
<input name="myInput"  type="text" size="20"/><br />
<input name="myInput"  type="text" size="20"/><br />
<input type="button" onclick="getElements()" value="how many name is ?"/>
<input type="button" onclick="getElementsByTagNames()" value="getElementsByTagName"/>
</body>
</html>

 

posted @ 2014-01-18 20:58  MMLoveMeMM  阅读(147)  评论(0)    收藏  举报