函数作用域和闭包

 1 //闭包 ，嵌套函数被导出到它所定义的作用域外时，以这种方法调用，叫做一个闭包
 2 function outA() {
 3     var x = 0;
 4     function inA() {
 5         x += 1;
 6         console.log("inA:x=" + x);
 7     }
 8     return inA;
 9 }
10 var funa = outA();
11 funa();
12 funa();
13 
14 
15 
16 function outC(obj) {
17     var x = 0;
18     function inA() {
19         x += 10;
20         console.log("inA:x=" + x);
21     }
22     function inB() {
23         x += 2;
24         console.log("inB:x=" + x);
25     }
26     obj.funa = inA;
27     obj.funb = inB;
28 }
29 var o = new Object();
30 outC(o);
31 o.funa();
32 o.funb();