js函数中变量的作用域

 1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
 2 "http://www.w3.org/TR/html4/loose.dtd">
 3 <html xmlns="http://www.w3.org/1999/xhtml">
 4     <head>
 5         <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 6         <title>New Web Project</title>
 7         <script type="text/javascript">
 8             function fun()
 9             {
10                 
11                 var a=10;//局部变量    显示声明
12                 b=20;//全局变量    隐式声明
13             }
14             fun();
15             //console.log("a="+a);
16             console.log("b="+b);
17         </script>
18     </head>
19     <body>
20         <h1>New Web Project Page</h1>
21     </body>
22 </html>
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