BigDecimal和BigInteger

最新推荐文章于 2025-04-18 21:08:16 发布

转载最新推荐文章于 2025-04-18 21:08:16 发布 · 227 阅读

本文详细介绍了Java中处理高精度数值的两个重要类——BigDecimal与BigInteger。通过具体示例展示了如何使用这两个类进行加减乘除等运算，并解释了它们在解决浮点数运算不精确问题上的应用。

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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

package BigDecimal;
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 Demo01 {
	@SuppressWarnings("deprecation")
	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));
	}
}

BigInteger:可以让超过Integer范围内的数据进行运算

*
* 构造方法：

* BigInteger(String val)

public BigInteger add(BigInteger val):加

* public BigInteger subtract(BigInteger val):减
* public BigInteger multiply(BigInteger val):乘
* public BigInteger divide(BigInteger val):除

* public BigInteger[] divideAndRemainder(BigInteger val):返回商和余数的数组

package BigInteger;

import java.math.BigInteger;

/*
 *  BigInteger:可以让超过Integer范围内的数据进行运算
 * 构造方法：
 * BigInteger(String val) 
 * 
 * public BigInteger add(BigInteger val):加
 * public BigInteger subtract(BigInteger val):减
 * public BigInteger multiply(BigInteger val):乘
 * public BigInteger divide(BigInteger val):除
 * public BigInteger[] divideAndRemainder(BigInteger val):返回商和余数的数组
 */
public class Demo01 {
	public static void main(String[] args) {
		BigInteger bi1 = new BigInteger("100");
		BigInteger bi2 = new BigInteger("50");

		// public BigInteger add(BigInteger val):加
		System.out.println("add:" + bi1.add(bi2));
		// public BigInteger subtract(BigInteger val):加
		System.out.println("subtract:" + bi1.subtract(bi2));
		// public BigInteger multiply(BigInteger val):加
		System.out.println("multiply:" + bi1.multiply(bi2));
		// public BigInteger divide(BigInteger val):加
		System.out.println("divide:" + bi1.divide(bi2));

		// public BigInteger[] divideAndRemainder(BigInteger val):返回商和余数的数组
		BigInteger[] bis = bi1.divideAndRemainder(bi2);
		System.out.println("商：" + bis[0]);
		System.out.println("余数：" + bis[1]);
	}
}