BigInteger compareTo() Method in Java

The java.math.BigInteger.compareTo(BigInteger value) method Compares this BigInteger with the BigInteger passed as the parameter. 

Syntax:

public int compareTo(BigInteger val)

Parameter: This method accepts a single mandatory parameter val which is the BigInteger to compare with BigInteger object. 

Return Type: This method returns the following:

• 0: if the value of this BigInteger is equal to that of the BigInteger object passed as a parameter.
• 1: if the value of this BigInteger is greater than that of the BigInteger object passed as a parameter.
• -1: if the value of this BigInteger is less than that of the BigInteger object passed as a parameter.

Examples:

Input: BigInteger1=2345, BigInteger2=7456
Output: -1
Explanation: BigInteger1.compareTo(BigInteger2)=-1.

Input: BigInteger1=9834, BigInteger2=7456
Output: 1
Explanation: BigInteger1.compareTo(BigInteger2)=1.

Example 1: Below programs illustrate the compareTo() method of BigInteger class when both BigIntegers are equal

Java

// 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");
        }
    }
}

Output:

BigInteger1 321456 and BigInteger2 321456 are equal

Example 2: when BigInteger1 is greater than BigInteger2 

Java

// 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);
        }

    }
}

Output:

BigInteger1 654321 is greater than BigInteger2 321456

Example 3: When BigInteger1 is lesser than BigInteger2 

Java

// 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);
        }
    }
}

Output:

BigInteger1 321456 is lesser than BigInteger2 564321