为什么写在函数外的话显示出来的是undefined,不应该是全局对象吗?
var bodyNode = document.getElementsByTagName("body")[0]; function createNode(){
alert(bodyNode);
}
var bodyNode = document.getElementsByTagName("body")[0]; function createNode(){
alert(bodyNode);
}
<html><head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>test</title></head><body></body>
<script>
var bodyNode = document.getElementsByTagName("body")[0];function createNode(){
alert(bodyNode);
}
createNode()
</script>
</html>
同上,先看看document.getElementsByTagName("body")是不是undefined
到它读var bodyNode = document.getElementsByTagName("body")[0];
这段代码时你没有加载body,所有为null