java进阶 -bigDecimal 41

 

 

 

 

package com.cyjt97.BD;

import java.math.BigDecimal;
import java.math.RoundingMode;

//BigDecimal解决小数不精准问题
public class day {
    public static void main(String[] args) {
        BigDecimal bd1 = BigDecimal.valueOf(10.0);
        BigDecimal bd2 = BigDecimal.valueOf(3.0);
//        第二位是精确到第几位
        System.out.println(bd1.divide(bd2,2, RoundingMode.HALF_UP));    //3.33
        System.out.println(bd1.divide(bd2,2, RoundingMode.UP));         //3.34  进一法
        System.out.println(bd1.divide(bd2,2, RoundingMode.HALF_DOWN));  //3.33
        BigDecimal res = bd1.divide(bd2,2,RoundingMode.HALF_UP);
        double s = res.doubleValue();
        Math.abs(s);

        jj();

    }

    private static void jj() {
        double num1 = 0.1;
        double num2 = 0.2;
        System.out.println(num1 + num2);
//        推荐方法
        BigDecimal BD1 = BigDecimal.valueOf(0.1);
        BigDecimal BD2 = BigDecimal.valueOf(0.2);
//        add加法
        System.out.println(BD1.add(BD2));//0.3
//        subtract减法
        System.out.println(BD1.subtract(BD2));//-0.1
//        multiply乘法
        System.out.println(BD1.multiply(BD2));//0.02
//        divide除法
        System.out.println(BD1.divide(BD2));//0.5
    }
}