The Logic Behind Even & Odd

In mathematics, an even number is an integer that is exactly divisible by 2. When you divide an even number by 2, the remainder is always 0. Conversely, an odd number leaves a remainder of 1.

Method 1: Using If-Else Statement

This is the most common and readable way for beginners to write the program.

import java.util.Scanner;

public class EvenOdd {
public static void main(String[] args) {
// Create Scanner object to read input
Scanner reader = new Scanner(System.in);

    System.out.print(<span class="string">"Enter a number: "</span>);
    <span class="keyword">int</span> num = reader.nextInt();

    <span class="keyword">if</span> (num % <span class="string">2</span> == <span class="string">0</span>) {
        System.out.println(num + <span class="string">" is Even"</span>);
    } <span class="keyword">else</span> {
        System.out.println(num + <span class="string">" is Odd"</span>);
    }
}
}

Method 2: Using Ternary Operator

A more concise way to write the same logic in a single line of code.

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

Method 3: Bitwise AND Operator

For advanced performance optimization, you can check the last bit of the number. If (num & 1) == 0, the number is even.