package cn.sasa.demo5;
import java.math.BigDecimal;
import java.math.BigInteger;
public class BigDataDemo {
public static void main(String[] args) {
//BigInteger
//数字太大,超过了long的范围
//long num1 = 9999999999999999999999999999999999999999999999L;
BigInteger num1 = new BigInteger("999999999999999999999999999999999477");
BigInteger num2 = new BigInteger("77777597111111111111111117777");
//加法
BigInteger addNum = num1.add(num2);
System.out.println(addNum);
//减法
BigInteger subNum = num1.subtract(num2);
System.out.println(subNum);
//乘法
BigInteger mulNum = num1.multiply(num2);
System.out.println(mulNum);
//除法
BigInteger divNum = num1.divide(num2);
System.out.println(divNum);
//BigDecimal
//double 会造成精度不准确
// double num3 = 0.01 + 0.09;
// System.out.println(num3);//0.09999999999999999
// System.out.println(0.03-0.01);//0.019999999999999997
// System.out.println(1.0023 * 100);//100.22999999999999
// System.out.println(1.301 / 100);//0.013009999999999999
BigDecimal deci1 = new BigDecimal("0.01");
BigDecimal deci2 = new BigDecimal("0.09");
BigDecimal addDeci = deci1.add(deci2);
System.out.println(addDeci);//0.10
BigDecimal deci3 = new BigDecimal("0.03");
BigDecimal deci4 = new BigDecimal("0.01");
BigDecimal subDeci = deci3.subtract(deci4);
System.out.println(subDeci);//0.02
BigDecimal deci5 = new BigDecimal("1.0023");
BigDecimal deci6 = new BigDecimal("100");
BigDecimal mulDeci = deci5.multiply(deci6);
System.out.println(mulDeci);//100.2300
BigDecimal deci7 = new BigDecimal("1.301");
BigDecimal diviDeci = divideBigDecimal(deci7, deci3);
System.out.println(diviDeci);
}
//BigDecimal 的除法运算
static BigDecimal divideBigDecimal(BigDecimal num1, BigDecimal num2) {
/**
* BigDecimal 除不尽会抛异常,解决方式:
* divide(divisor, scale, roundingMode)
* divisor 除数
* scale 保留几位小数
* roundingMode 保留模式
* static int ROUND_UP 向上+1
* static int ROUND_DOWN 直接舍去
* static int ROUND_HALF_UP >= 0.5 向上+1
* static int ROUND_HALF_DOWN > 0.5 向上+1 ,否则直接舍去
*/
@SuppressWarnings("deprecation")
BigDecimal rs = num1.divide(num2, 2, BigDecimal.ROUND_DOWN); //jdk9 之后会警告这个方法已过期
//BigDecimal rs = num1.divide(num2);
return rs;
}
}