Java Guava | mod(long x, long m) of LongMath Class with Examples

The mod(long x, long m) method of Guava’s LongMath Class accepts two parameters x and m, and used to calculate the value of x modulus under m.

Syntax:

public static long mod(long x, long m)

Parameters: This method accepts two parameters x and m which are of long type to calculate x modulo m.

Return Value: The method returns x mod m that will be a non-negative value less than m.

Exception: The method mod(long x, long m) throws ArithmeticException if m <= 0.

Below examples illustrate the mod(long x, long m) method:

Example 1 :

// Java code to show implementation of
// mod(long x, long m) method of Guava's
// LongMath class
import java.math.RoundingMode;
import com.google.common.math.LongMath;

class GFG {

    // Driver code
    public static void main(String args[])
    {
        long x1 = -77;
        long m1 = 4;

        long ans1 = LongMath.mod(x1, m1);

        // Using mod(long x, long m)
        // method of Guava's LongMath class
        System.out.println(x1 + " mod "
                           + m1 + " is : " + ans1);

        long x2 = 22;
        long m2 = 6;

        long ans2 = LongMath.mod(x2, m2);

        // Using mod(long x, long m)
        // method of Guava's LongMath class
        System.out.println(x2 + " mod "
                           + m2 + " is : " + ans2);
    }
}

Output:

-77 mod 4 is : 3
22 mod 6 is : 4

Example 2:

// Java code to show implementation of
// mod(long x, long m) method of Guava's
// LongMath class
import java.math.RoundingMode;
import com.google.common.math.LongMath;

class GFG {

    static long findMod(long x, long m)
    {
        try {
            // Using mod(long x, long m)
            // method of Guava's LongMath class
            // This should throw "ArithmeticException"
            // as m <= 0
            long ans = LongMath.mod(x, m);

            // Return the answer
            return ans;
        }
        catch (Exception e) {
            System.out.println(e);
            return -1;
        }
    }

    // Driver code
    public static void main(String args[])
    {
        long x = 11;
        long m = -5;

        try {
            // Function calling
            findMod(x, m);
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

Output:

java.lang.ArithmeticException: Modulus must be positive

Reference: https://google.github.io/guava/releases/20.0/api/docs/com/google/common/math/LongMath.html#mod-long-int-