abstract：<!DOCTYPE html><html><head><title>javascript基础</title><!-- <script type="text/javascript">document.write('javascript的基础语')</script> -->
<!DOCTYPE html>
<html>
<head>
<title>javascript基础</title>
<!-- <script type="text/javascript">document.write('javascript的基础语')</script> -->
</head>
<body>
<script type="text/javascript">
//*document.write('javascript的基础')*//
var y=5,x=10;
z=x-y
document.write(z)
</script>
</body>
</html>
Correcting teacher：天蓬老师Correction time：2019-06-03 10:25:27
Teacher's summary：var y=5,x=10;
z=x-y
document.write(z)
这个代码有2个问题.
1. 会自动创建全局变量z;
2. 应该将结果输出到控制吧查看
