Java BigInteger类概述及其构造方法

BigInteger类

• BigInteger类概述

可以让超过 Integer 范围内的数据进行运算

• 构造方法

                 public BigInteger(String val)

 代码测试如下：

package cn.wen_01;

import java.math.BigInteger;

public class BigIntegerDemo {
	public static void main(String[] args) {
		// 测试，是为了简单了解超过int范围内，Integer就不能再表示，所以就更谈不上计算了。
		// Integer i = new Integer(100);
		// System.out.println(i);
		// // System.out.println(Integer.MAX_VALUE);
		// Integer ii = new Integer("2147483647");
		// System.out.println(ii);
		// // NumberFormatException
		// Integer iii = new Integer("2147483648");
		// System.out.println(iii);    //出现异常

		// 通过大整数来创建对象
		BigInteger bi = new BigInteger("2147483648");
		System.out.println("bi:" + bi);
	}
}

• BigInteger类成员方法

1. public BigInteger add(BigInteger val)
2. public BigInteger subtract(BigInteger val)
3. public BigInteger multiply(BigInteger val)
4. public BigInteger divide(BigInteger val)
5. public BigInteger[] divideAndRemainder(BigInteger val)

package cn.wen_02;

import java.math.BigInteger;

/*
 * 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 BigIntegerDemo {
	public static void main(String[] args) {
		BigInteger bi1 = new BigInteger("100");
		BigInteger bi2 = new BigInteger("50");

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

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

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

		// public BigInteger divide(BigInteger val)
		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]);    //2
		System.out.println("余数：" + bis[1]);    //0
	}
}