摘要：<!DOCTYPE html><html><head><meta charset="UTF-8"><title>声明变量</title></head><body><script type="text/javascript">var num = 0;al
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>声明变量</title>
</head>
<body>
<script type="text/javascript">
var num = 0;
alert(typeof num);
</script>
</body>
</html>
批改老师：天蓬老师批改时间：2018-12-30 13:39:23
老师总结：变量声明的时候,一定要有var 关键字,不管是在全局,还是函数中,一定要这样做,这样才能和一个作用域进行绑定
