輕鬆搞定Math.ceil,Math.round,Math.floor三者的區別

   double a = 0.1;
        double b = 0.50;
        double c = 0;
        double d = 0.4;
        double e = 0.6;
        double f = 1.3;
        double g = 1.6;

        //Math.ceil 表示的是大於某個小數的最小整數的double值;  ceiling最高限度 天花板
        double ceil1 = Math.ceil(a);
        double ceil2 = Math.ceil(b);
        double ceil3 = Math.ceil(c);
        double ceil4 = Math.ceil(d);
        double ceil5 = Math.ceil(e);

        //Math.round  表示的是四捨五入,且得到long值
        long round1 = Math.round(a);
        long round2 = Math.round(b);
        long round3 = Math.round(c);
        long round4 = Math.round(d);
        long round5 = Math.round(e);

        //Math.floor 跟Math.ceil相反,表示的是小於某個小數的最大整數值的double類型; floor底板 最底限度
        double floor1 = Math.floor(a);
        double floor2 = Math.floor(b);
        double floor3 = Math.floor(c);
        double floor4 = Math.floor(d);
        double floor5 = Math.floor(e);
        double floor6 = Math.floor(f);
        double floor7 = Math.floor(g);