<!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>
