函数 闭包

 function a() {
            function b() {
                var bbb = 234;
                console.log(aaa);
            }
            var aaa = 123;
            return b;
        }
        var glob = 100;
        var dome = a();
        dome();

 function test() {
            var num = 100;
            function a() {
                num++;
                console.log(num);
            }
            function b() {
                num--;
                console.log(num);
            }
            return [a, b]

        }
        var myArr = test();
        myArr[0]();  //101
        myArr[1]();  //100