JS函数04 

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
    </head>
    <body>
        <script type="text/javascript">
            //全局变量和局部变量的区别
/*            function test(){
                var x=1;
                alert(x);
            }
            test();
            alert(x);    //取不到变量，报错*/
            function test(){
                y=5;
                alert(y);
            }
//            test();
//            alert(y);
        var x=1,y=2;
        function calc(x,y){
            document.write('a的值为'+a+'<br/>');//undefined
            document.write('函数体内x的值为：'+x+'<br/>'); //1
            document.write('函数体内y的值为：'+y+'<br/>'); //2
            var x=0,y=6;
            z=x+y;
            x=x+y;
            var a=198;
            document.write('a的值为：'+a+'<br/>'); //198
            document.write('x的值为：'+x+'<br/>'); //6
            return z;
        }
        //alert(calc(x,y));
        //alert(x+'-'+y+'-'+z);
        var a=1,b=2;
        function test1(){
            var a=5,b=10;
            return a+b;

        }
        function test2(){
            var a=11,b=22;
            return a+b;
        }
        alert(test1());
        alert(test2());
        alert(a+'--'+b);
            
        </script>
    </body>
</html>

 

posted @ 2018-08-27 23:14  冯志国  阅读(111)  评论(0)    收藏  举报