Example: CheckVowelConsonantSet in Java

// CheckVowelConsonantSet
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        // Step 1: Create a Scanner object
        Scanner scanner = new Scanner(System.in);

        // Step 2: Prompt for character input
        System.out.print("Enter a character: ");
        char ch = scanner.next().charAt(0);

        // Step 3: Check if it's an alphabet
        if (!Character.isLetter(ch)) {
            System.out.println(ch + " is not an alphabet.");
            scanner.close();
            return;
        }

        // Step 4: Create a Set of vowels (case-insensitive for comparison)
        Set<Character> vowels = new HashSet<>();
        vowels.add('a');
        vowels.add('e');
        vowels.add('i');
        vowels.add('o');
        vowels.add('u');

        // Step 5: Convert the input character to lowercase for consistent checking
        char lowerCaseCh = Character.toLowerCase(ch);

        // Step 6: Check if the lowercase character is present in the set of vowels
        if (vowels.contains(lowerCaseCh)) {
            System.out.println(ch + " is a Vowel.");
        } else {
            System.out.println(ch + " is a Consonant.");
        }

        // Step 7: Close the scanner
        scanner.close();
    }
}