Math floorMod() Method in Java

The java.lang.Math.floorMod() is a built-in math function in java which returns the floor modulus of the integer arguments passed to it. Therefore, floor modulus is (a – (floorDiv(a, b) * b)), has the same sign as the divisor b, and is in the range of -abs(b) < t < +abs(b).

Relationship between floorDiv and floorMod is:

floorDiv(a, b) * b + floorMod(a, b) == a

The difference in values between floorMod and the % operator is due to the difference between floorDiv that returns the integer less than or equal to the quotient and the / operator that returns the integer closest to zero.

Syntax :

public static int floorMod(data_type a, data_type b)

Parameters: The function accepts two parameters.

• a: This refers to the dividend value.
• b: This refers to the divisor value.

The parameters can be of data-type int or long.

Exception: It throws an ArithmeticException if the divisor is zero.

Return Value: This method returns the floor modulus x – (floorDiv(x, y) * y).

Below programs are used to illustrate the working of java.lang.Math.floorMod() method.
Program 1:

// Java program to demonstrate working
// of java.lang.Math.floorMod() method
import java.lang.Math;

class Gfg1 {

    public static void main(String args[])
    {
        int a = 25, b = 5;
        System.out.println(Math.floorMod(a, b));

        // Divisor and dividend is having same sign
        int c = 123, d = 50;
        System.out.println(Math.floorMod(c, d));

        // Divisor is having negative sign
        int e = 123, f = -50;
        System.out.println(Math.floorMod(e, f));

        // Dividend is having negative sign
        int g = -123, h = 50;
        System.out.println(Math.floorMod(g, h));
    }
}

Output:

0
23
-27
27

Program 2:

// Java program to demonstrate working
// of java.lang.Math.floorMod() method
import java.lang.Math;

class Gfg2 {

    public static void main(String args[])
    {
        int x = 200;
        int y = 0;

        System.out.println(Math.floorMod(x, y));
    }
}

Output:

Runtime Error :
Exception in thread "main" java.lang.ArithmeticException: / by zero
    at java.lang.Math.floorDiv(Math.java:1052)
    at java.lang.Math.floorMod(Math.java:1139)
    at Gfg2.main(File.java:13)

Reference: https://docs.oracle.com/javase/8/docs/api/java/lang/Math.html#floorMod-int-int-