Modulo or Remainder Operator in Java

The modulo operator (%) in Java is an arithmetic operator used to find the remainder after division of one number by another. It is commonly used in mathematical calculations, loops, condition checking, and number-based logic.

class Test {
    public static void main(String[] args) {
        int a = 10, b = 3;
        System.out.println(a % b);
    }
}

1

Explanation: 10 ÷ 3 = 3 with a remainder of 1.

Syntax:

A % B
Where A is the dividend and B is divisor

Example 1: Modulo with Negative Numbers

class Example {
    public static void main(String[] args) {
        System.out.println(10 % 3);
        System.out.println(-10 % 3);
        System.out.println(10 % -3);
        System.out.println(-10 % -3);
    }
}

1
-1
1
-1

Explanation:

• The sign of the result depends on the dividend.
• Divisor’s sign does not affect the sign of the remainder.

Example 2: Modulo with Floating-Point Numbers

class FloatModulo {
    public static void main(String[] args) {
        double x = 10.5, y = 3.2;
        System.out.println(x % y);
    }
}

0.8999999999999995

Explanation: Java allows % with floating-point values, though results may show precision issues due to binary representation.

Note:

• Division by zero (a % 0) throws an ArithmeticException.
• % works with int, long, float, and double.
• Modulo is not a percentage operator.

Difference Between Modulo and Division