BigDecimal类的加减乘除

package ss1;

import java.math.BigDecimal;

/*
 * 构造方法：
 *   public BigDecimal(String val)
 *
 * public BigDecimal add(BigDecimal augend)
 * public BigDecimal subtract(BigDecimal subtrahend)
 * public BigDecimal multiply(BigDecimal multiplicand)
 * public BigDecimal divide(BigDecimal divisor)
 * public BigDecimal divide(BigDecimal divisor,int scale,int roundingMode):商，几位小数，如何舍取
 */
public class Menu {
 public static void main(String[] args) {
  // System.out.println(0.09 + 0.01);
   // System.out.println(1.0 - 0.32);
   // System.out.println(1.015 * 100);
   // System.out.println(1.301 / 100);

   BigDecimal bd1 = new BigDecimal("0.09");
   BigDecimal bd2 = new BigDecimal("0.01");
   System.out.println("add:" + bd1.add(bd2));
   System.out.println("-------------------");

   BigDecimal bd3 = new BigDecimal("1.0");
   BigDecimal bd4 = new BigDecimal("0.32");
   System.out.println("subtract:" + bd3.subtract(bd4));
   System.out.println("-------------------");

   BigDecimal bd5 = new BigDecimal("1.015");
   BigDecimal bd6 = new BigDecimal("100");
   System.out.println("multiply:" + bd5.multiply(bd6));
   System.out.println("-------------------");

   BigDecimal bd7 = new BigDecimal("1.301");
   BigDecimal bd8 = new BigDecimal("100");
   System.out.println("divide:" + bd7.divide(bd8));
   System.out.println("divide:"
     + bd7.divide(bd8, 3, BigDecimal.ROUND_HALF_UP));
   System.out.println("divide:"
     + bd7.divide(bd8, 8, BigDecimal.ROUND_HALF_UP));
  }
 }
结果:

add:0.10
-------------------
subtract:0.68
-------------------
multiply:101.500
-------------------
divide:0.01301
divide:0.013
divide:0.01301000