常見物件-BigInteger

package cn.itcast_01;

import java.math.BigInteger;

/*
 * BigInteger:可以讓超過Integer範圍內的資料進行運算
 * 
 * 構造方法：
 * BigInteger(String val) 
 */
public class BigIntegerDemo {
	public static void main(String[] args) {
		// 這幾個測試，是為了簡單超過int範圍內，Integer就不能再表示，所以就更談不上計算了。
		Integer i = new Integer(100);
		System.out.println(i);                    //100
		System.out.println(Integer.MAX_VALUE);    //2147483647
		
		Integer ii = new Integer("2147483647");
		System.out.println(ii);                   //2147483647
		
		//Integer iii = new Integer("2147483648");
		//System.out.println(iii);                //NumberFormatException

		// 通過大整數來建立物件
		BigInteger bi = new BigInteger("2147483648");
		System.out.println("bi:" + bi);           //bi:2147483648
	}
}

package cn.itcast_02;

import java.math.BigInteger;

/*
 * public BigInteger add(BigInteger val):加
 * public BigInteger subtract(BigInteger val):減
 * public BigInteger multiply(BigInteger val):乘
 * public BigInteger divide(BigInteger val):除
 * public BigInteger[] divideAndRemainder(BigInteger val):返回商和餘數的陣列
 */
public class BigIntegerDemo {
	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));           //add:150
		
		// public BigInteger subtract(BigInteger val):減
		System.out.println("subtract:" + bi1.subtract(bi2)); //subtract:50
		
		// public BigInteger multiply(BigInteger val):乘
		System.out.println("multiply:" + bi1.multiply(bi2)); //multiply:5000
		
		// public BigInteger divide(BigInteger val):除
		System.out.println("divide:" + bi1.divide(bi2));     //divide:2

		// public BigInteger[] divideAndRemainder(BigInteger val):返回商和餘數的陣列
		BigInteger[] bis = bi1.divideAndRemainder(bi2);
		System.out.println("商：" + bis[0]);                  //商：2
		System.out.println("餘數：" + bis[1]);                //餘數：0    
	}
}