测试类

package com.imooc.chapter15test;

public class MathTest {
    public static void main(String[] args) {
        //创建样本double数组
        float[] sample = {99.5f, 188.56f, 50.12f, 108.6f, 23.42f, 360.9f, 15f, 38.38f, 88.8f, 125.6f};
        
        //创建处理方式String类型数组
        String[] method = {"向上取整","向下取整","四舍五入"};
        
        //创建销售金额变量
        double  sampleAmount;
        
        //先循环处理方式，然后进行该方式的数学运算并累计金额，最后输出
        for (String str:
             method) {
            switch(str){
                case "向上取整":
                    System.out.println("向上取整的销售金额: " + ceilCalculate(sample));
                    break;
                case "向下取整":
                    System.out.println("向下取整的销售金额: " + floorCalculate(sample));
                    break;
                case "四舍五入":
                    System.out.println("四舍五入的销售金额: " + roundCalculate(sample));
                    break;
            }
        }
    }

    /**
     * 向上取整并累加输出金额
     * @param floats 销售金额数组
     * @return 销售金额总计
     */
    public static double ceilCalculate(float[] floats){
            double sum = 0;
        for (float item:
             floats) {
            sum += Math.ceil(item);
        }
            return sum;
    }

    /**
     * 向下取整并累加输出金额
     * @param floats 销售金额数组
     * @return 销售金额总计
     */
    public static double floorCalculate(float[] floats){
            double sum = 0;
            for (float item:
                    floats) {
                sum += Math.floor(item);
            }
            return sum;
    }
    /**
     * 四舍五入并累加输出金额
     * @param floats 销售金额数组
     * @return 销售金额总计
     */
    public static double roundCalculate(float[] floats){
        double sum = 0;
        for (float item:
                floats) {
            sum += Math.round(item);
        }
        return sum;
    }
}