Java BigInteger compareTo()方法

java.math.BigInteger.compareTo(BigInteger value) 方法将这个BigInteger与作为参数传递的BigInteger进行比较。

语法

public int compareTo(BigInteger val)

参数： 该方法接受一个强制参数 val ，即要与BigInteger对象进行比较的BigInteger。

返回类型： 该方法返回以下内容。

• 0 : 如果这个BigInteger的值与作为参数传递的BigInteger对象的值相等。
• 1 : 如果这个BigInteger的值大于作为参数传递的BigInteger对象的值。
• -1 : 如果这个BigInteger的值小于作为参数传递的BigInteger对象的值。

例子

输入: BigInteger1=2345, BigInteger2=7456
输出： -1
解释: BigInteger1.compareTo(BigInteger2)=-1.

输入: BigInteger1=9834, BigInteger2=7456
输出： 1
解释: BigInteger1.compareTo(BigInteger2)=1.

例1：下面的程序说明了当两个BigIntegers相等时，BigInteger类的compareTo()方法 。

// Java program to demonstrate
// compareTo() method of BigInteger
 
import java.math.BigInteger;
 
public class GFG {
 
    public static void main(String[] args)
    {
        // Creating 2 BigInteger objects
        BigInteger b1, b2;
 
        b1 = new BigInteger("321456");
        b2 = new BigInteger("321456");
 
        // apply compareTo() method
        int comparevalue = b1.compareTo(b2);
 
        // print result
        if (comparevalue == 0) {
 
            System.out.println("BigInteger1 "
                               + b1 + " and BigInteger2 "
                               + b2 + " are equal");
        }      
    }
}

输出

BigInteger1 321456 and BigInteger2 321456 are equal

例2：当BigInteger1大于BigInteger2时

// Java program to demonstrate
// compareTo() method of BigInteger
 
import java.math.BigInteger;
 
public class GFG {
 
    public static void main(String[] args)
    {
        // Creating 2 BigInteger objects
        BigInteger b1, b2;
 
        b1 = new BigInteger("654321");
        b2 = new BigInteger("321456");
 
        // apply compareTo() method
        int comparevalue = b1.compareTo(b2);
 
        // print result
        if (comparevalue == 1) {
 
            System.out.println("BigInteger1 " + b1 + "
                is greater than BigInteger2 " + b2);
        }
        
    }
}

输出

BigInteger1 654321 is greater than BigInteger2 321456

例3：当BigInteger1小于BigInteger2时

// Java program to demonstrate
// compareTo() method of BigInteger
 
import java.math.BigInteger;
 
public class GFG {
 
    public static void main(String[] args)
    {
        // Creating 2 BigInteger objects
        BigInteger b1, b2;
 
        b1 = new BigInteger("321456");
        b2 = new BigInteger("564321");
 
        // apply compareTo() method
        int comparevalue = b1.compareTo(b2);
 
        // print result       
        if(comparevalue == -1) {
 
            System.out.println("BigInteger1 " + b1 + "
                 is lesser than BigInteger2 " + b2);
        }
    }
}

输出

BigInteger1 321456 is lesser than BigInteger2 564321