java BigInteger類的用法

import java.math.BigInteger;

Scanner in = new Scanner(System.in);
BigInteger x1 = new BigInteger("-11"); //新建一個對象
BigInteger x2 = in.nextBiginteger();//鍵盤輸入
BigInteger y = x1.abs(); //取絕對值
BigInteger y2 = x1.add(y); //x+y
int x3 = y.compareTo(x1); //x和y比較 < == >分別返回 -1,0,1
Boolean x4 = (y.compareTo(x1) <= 0); //判斷y是否<=x 0是固定不變的，<=符號可以隨意變
BigInteger x5 = y.divide(x1);  //    y/x1
BigInteger x6 = y.multiply(x1);// y*x1
double x6 = x2.doubleValue(); //將x2轉化為double類型，轉化為int用intValue（）
BigInteger x7 = x2.gcd(x1);// 返回abs(x2)和abs(x1)的最大公約數
BigInteger x8 = x2.negate();// 返回-x2
String x9 = x2.toString();// 將x2轉化為字符串
BigInteger y3 = x2.reamainder(x1);// 返回x2%x1
BigInteger y4= x1.pow(2);// pow(int exponent) 返回其值為 (this^exponent) 的 BigInteger。