封装高质量的代码

封装星期，利用map数据结构
优点：遍历更快

        var weekMap = new Map();

        weekMap.set(0,"星期日");
        weekMap.set(1,"星期一");
        weekMap.set(2,"星期二");
        weekMap.set(3,"星期三");
        weekMap.set(4,"星期四");
        weekMap.set(5,"星期五");
        weekMap.set(6,"星期六");
        function getWeek(w){
            return weekMap.get(w);
        }