日期:2014-05-16 浏览次数:20413 次
var k;
var a = {};
for(var i in a){
k++;
}
if(k == 0){
return;
}
------解决方案--------------------
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title> New Document </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>
<script type="text/javascript">
function objIsNull(obj){
if(obj){
alert("This obj is exist!");
}else{
alert("This obj is null");
}
}
</script>
<body>
<!--不为null的例子-->
<input type="button" value="exist" onclick="objIsNull(this)"/>
<!--为null的例子-->
<input type="button" value="null" onclick="objIsNull()"/>
</body>
</html>