Java Program to Check If a Number is Even or Odd Full Guide

Here's a Java program with clear guidance and comments for students on how to check if a number is even or odd. The program includes detailed explanations in the code, so it's easy to understand the logic behind it.

import java.util.Scanner; // Import Scanner class for taking user input

public class EvenOddChecker {

    // Main method is the entry point of any Java program
    public static void main(String[] args) {
        // Create a Scanner object to get user input
        Scanner scanner = new Scanner(System.in);
        
        // Provide guidance to the user
        System.out.println("Welcome to the Even or Odd Number Checker!");
        System.out.println("Please enter a number to check whether it is even or odd:");
        
        // Taking input from the user
        int number = scanner.nextInt(); // .nextInt() reads an integer from the user

        // Check if the number is even or odd using the modulo operator
        if (number % 2 == 0) { 
            // If the remainder when divided by 2 is 0, it is an even number
            System.out.println("The number " + number + " is EVEN.");
        } else {
            // If the remainder when divided by 2 is not 0, it is an odd number
            System.out.println("The number " + number + " is ODD.");
        }
        
        // Close the scanner to avoid resource leaks
        scanner.close();
    }
}

Explanation:

1. Imports:

   • import java.util.Scanner; — This line imports the Scanner class which is used to read user input from the console.

2. Scanner Object:

   • Scanner scanner = new Scanner(System.in); — Creates a scanner object to allow input from the user.

3. User Prompt:

   • System.out.println("Please enter a number to check whether it is even or odd:"); — This gives clear instructions to the user on what to do.

4. Input:

   • int number = scanner.nextInt(); — This reads an integer input from the user and stores it in the variable number.

5. Checking Even or Odd:

   • if (number % 2 == 0) — This checks whether the number is divisible by 2 with no remainder. If true, the number is even.
   • else — If the condition above is false, it implies the number is odd.

6. Output:

   • System.out.println("The number " + number + " is EVEN."); — Prints the result based on the check.
   • System.out.println("The number " + number + " is ODD."); — Prints the result if the number is odd.

7. Closing Scanner:

   • scanner.close(); — Closes the scanner to release the resources.

How to Run the Program:

1. Copy the code into a Java file (e.g., EvenOddChecker.java).
2. Compile the program using javac EvenOddChecker.java in the terminal.
3. Run the program using java EvenOddChecker.
4. Enter any integer when prompted to check whether it's even or odd.

This program is simple yet informative, with comments that explain each step for students learning Java.