js模块化 中的变量可在局部 中的‘全局共享’

  var operafn = (function () {
        var obj = {'a':6,'b':8}
        var add = function () {
            obj.a++;
            console.log(obj);
        }

        var jian = function () {
            obj.a--;
            console.log(obj);

        }
        var cheng = function () {
            obj.a*= 5;
            console.log(obj);

        }
        return {
            add:add,
            jian:jian,
            cheng:cheng
        }
    })()
    operafn.add();//{a: 7, b: 8}
    operafn.jian();//{a: 6, b: 8}
    operafn.cheng();//{a: 30, b: 8}