<script>

        //java.utils.ArrayList()

        //包（命名空间）

        /*

        var java = {};

        java.utils = {};

        java.utils.ArrayList = "asdfafsd";

        java.utils.ArrayList;

        */

        //

        (

        function(){

            var a = 5;

            var b = 100;

            window.c = 200;//把c暴露出去

            d = 300;//这行代码也可以做到公布

        }

        )();

        //console.log(c);

        var result = (function(m,n){

                return m + n;})(10,20);

        //console.log(result);

        function Person(){

            var age = 1;

            this.getAge = function(){

                return age ;

            }

            this.setAge = function(val){

                   age = val;

            }

        }

        var p = new Person();

        p.setAge(20);

        console.log(p.getAge());

        //Closure 闭包

    </script>