Check Even or Odd in Java

🔢 Even or Odd Numbers

A number is even if divisible by 2 with no remainder, otherwise it's odd. Java uses the modulus operator (%) to check remainders and determine even/odd numbers easily.


// Check if number is even or odd
if (number % 2 == 0) {
    System.out.println("Even");
} else {
    System.out.println("Odd");
}

Different Approaches

%

Modulus Operator

Most common method using %

if (num % 2 == 0) {
    System.out.println("Even");
} else {
    System.out.println("Odd");
}

🔄

Method Approach

Create reusable method

public static boolean isEven(int n) {
    return n % 2 == 0;
}
System.out.println(isEven(10));

🎯

Ternary Operator

Compact conditional statement

String result = (num % 2 == 0) ? 
    "Even" : "Odd";
System.out.println(result);

⚡

Bitwise AND

Alternative using bitwise operation

if ((num & 1) == 0) {
    System.out.println("Even");
} else {
    System.out.println("Odd");
}

🔹 Complete Example Program

Here's a complete Java program to check even or odd numbers:

import java.util.Scanner;

public class EvenOdd {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();
        
        if (number % 2 == 0) {
            System.out.println(number + " is an even number.");
        } else {
            System.out.println(number + " is an odd number.");
        }
        
        // Alternative using method
        checkEvenOdd(number);
        
        scanner.close();
    }
    
    public static void checkEvenOdd(int num) {
        String result = (num % 2 == 0) ? "even" : "odd";
        System.out.println("Using method: " + num + " is " + result);
    }
}

Sample Output:

Enter a number: 17

17 is an odd number.

Using method: 17 is odd

🔹 Understanding the Logic

How Modulus Works:

Even numbers: 2, 4, 6, 8... when divided by 2 give remainder 0
Odd numbers: 1, 3, 5, 7... when divided by 2 give remainder 1
Modulus operator (%): Returns the remainder after division
Example: 10 % 2 = 0 (even), 11 % 2 = 1 (odd)

Bitwise AND Method:

Uses the fact that even numbers have 0 in the least significant bit
Odd numbers have 1 in the least significant bit
Slightly faster but less readable than modulus