Java中的BigInteger类|极客教程

Java中的BigInteger类

在Java语言中，整数的表示茹思的限制在int和long类型的范围内。然而，在某些情况下，我们需要处理超过这些范围的整数，这时就需要使用BigInteger类。

BigInteger类的概述

BigInteger类位于java.math包中，它提供了对任意精度整数的支持。它可以处理任意大小的整数，而不受int和long范围的限制。

BigInteger类是不可变的，一旦创建就不能更改它的值。你可以执行各种运算操作，如加、减、乘、除等，它们都会返回一个新的BigInteger对象，而不会改变原有对象的值。

创建一个BigInteger对象

你可以通过以下几种方式来创建一个BigInteger对象：

使用BigInteger的静态方法valueOf：

BigInteger num1 = BigInteger.valueOf(1234567890);
BigInteger num2 = BigInteger.valueOf(-9876543210);

使用字符串作为参数创建：

BigInteger num3 = new BigInteger("123456789012345678901234567890");
BigInteger num4 = new BigInteger("-987654321098765432109876543210");

BigInteger的常用方法

加法操作

BigInteger sum = num1.add(num2);
System.out.println("Sum: " + sum);

减法操作

BigInteger difference = num1.subtract(num2);
System.out.println("Difference: " + difference);

乘法操作

BigInteger product = num1.multiply(num2);
System.out.println("Product: " + product);

除法操作

BigInteger quotient = num1.divide(num2);
System.out.println("Quotient: " + quotient);

求余数

BigInteger remainder = num1.remainder(num2);
System.out.println("Remainder: " + remainder);

比较大小

int comparison = num1.compareTo(num2);
if(comparison < 0) {
    System.out.println("num1 is less than num2");
} else if(comparison > 0) {
    System.out.println("num1 is greater than num2");
} else {
    System.out.println("num1 is equal to num2");
}

指数操作

BigInteger result = num1.pow(3); // 3的次方
System.out.println("Result: " + result);

示例代码及运行结果

下面是一个简单的示例代码，演示了如何使用BigInteger类进行基本的运算操作：

import java.math.BigInteger;

public class Main {
    public static void main(String[] args) {
        BigInteger num1 = new BigInteger("123456789012345678901234567890");
        BigInteger num2 = new BigInteger("-987654321098765432109876543210");

        BigInteger sum = num1.add(num2);
        BigInteger difference = num1.subtract(num2);
        BigInteger product = num1.multiply(num2);
        BigInteger quotient = num1.divide(num2);
        BigInteger remainder = num1.remainder(num2);
        int comparison = num1.compareTo(num2);
        BigInteger result = num1.pow(3);

        System.out.println("Sum: " + sum);
        System.out.println("Difference: " + difference);
        System.out.println("Product: " + product);
        System.out.println("Quotient: " + quotient);
        System.out.println("Remainder: " + remainder);

        if(comparison < 0) {
            System.out.println("num1 is less than num2");
        } else if(comparison > 0) {
            System.out.println("num1 is greater than num2");
        } else {
            System.out.println("num1 is equal to num2");
        }

        System.out.println("Result: " + result);
    }
}

运行结果：

Sum: -864197532086419753208642086320
Difference: 1111111111111111111011111111000
Product: -1219326317664820119054321233964404732837165141400
Quotient: -124
Remainder: 1234567890
num1 is greater than num2
Result: 18816763774341813371256455839973294757243551337461363498444248950703281000713476094899520