JavaScript 计算星座和生肖

<script type="text/javascript">var Calculator = function () {
        /* *
         *  计算生肖
         *
         *      支持简写生日，比如01，转换为2001，89转换为1989；
         *      支持任何可以进行时间转换的格式，比如'1989/01/01','1989 01'等
         *
         * */
        function getShengXiao(birth) {
            birth += '';
            var len = birth.length;
            if (len < 4 && len != 2) {
                return false;
            }
            if (len == 2) {
                birth - 0 > 30 ? birth = '19' + birth : birth = '20' + birth;
            }
            var year = (new Date(birth)).getFullYear();
            var arr = ['猴', '鸡', '狗', '猪', '鼠', '牛', '虎', '兔', '龙', '蛇', '马', '羊'];
            return /^\d{4}$/.test(year) ? arr[year % 12] : false;
        }

        /* *
         *  计算星座
         *
         *      支持传递[月日]，[月,日]，[年月日]等格式，详见例子
         *
         * */
        function getAstro() {
            var params = {};
            var c = function (d) {
                return parseInt(d, 10);
            }
            switch (arguments.length) {
                case 1:
                    var s = arguments[0] + '', b = s.length;
                    if (b < 3 || b > 8) {
                        return false;
                    }
                    if (b == 3) {
                        params['mouth'] = c(s.slice(0, 1));
                    } else if (b == 4) {
                        params['mouth'] = c(s.slice(0, 2));
                    } else if (b == 6) {
                        params['mouth'] = c(s.slice(2, 4));
                    } else if (b == 8) {
                        params['mouth'] = c(s.slice(4, 6));
                    }
                    params['day'] = c(s.slice(-2));
                    break;
                case 2:
                    params['month'] = c(arguments[0]);
                    params['day'] = c(arguments[1]);
                    break;
                default :
                    return false;
                    break;
            }
            return "魔羯水瓶双鱼牡羊金牛双子巨蟹狮子处女天秤天蝎射手魔羯".substr(params['month'] * 2 - (params['day'] < [20, 19, 21, 21, 21, 22, 23, 23, 23, 23, 22, 22][params['month'] - 1] ? 2 : 0), 2);
        }

        return{
            shengxiao: getShengXiao,
            astro: getAstro
        }
    }()

    //例子：计算生肖
    console.log(Calculator.shengxiao(1989));
    console.log(Calculator.shengxiao('1989 01'));
    console.log(Calculator.shengxiao('1989-01'));
    console.log(Calculator.shengxiao('1989-01-01'));

    //例子：计算星座
    console.log(Calculator.astro('102'));       //01-02
    console.log(Calculator.astro('0102'));      //01-02
    console.log(Calculator.astro('1023'));      //10-22
    console.log(Calculator.astro('890102'));    //01-01
    console.log(Calculator.astro('19890102'));  //01-01
    console.log(Calculator.astro(1, 2));        //01-02
    console.log(Calculator.astro(01, 22));      //01-22</script>