parentElement() 顯示比myP大一層的標籤
children() 顯示再往下一層找
contains(): 檢查是否有子標籤(傳回true or flase)
source:
<html>
<head>
<title>存取父元素和子元素</title>
<script language="JavaScript">
function showParentTag(){
alert(myP.parentElement.tagName);
}
function showChildsTag(){
var strTags = "";
for (var i=0; i<myP.children.length; i++){
strTags += myP.children.item(i).tagName + " ";
}
alert(strTags);
}
function checkChild(){
var objEle = document.all("myP").children.item(1);
if (document.all("myP").contains(objEle))
alert("myP有子元素" + objEle.tagName);
else
alert("myP沒有子元素" + objEle.tagName);
}
</script>
</head>
<body id="myBody">
<h2 id="myH2">存取父元素和子元素</h2>
<hr>
<p id="myP">存取<b><i>HTML</i></b>文件的<b>父元素</b>和<i>子元素</i></p>
<form>
<input type="button" onclick="showParentTag()" value="取得父元素">
<input type="button" onclick="showChildsTag()" value="顯示子元素">
<input type="button" onclick="checkChild()" value="檢查是否有子元素">
</form>
</body>
</html>
