Example: CheckVowelConsonantStringIndexOf in Java

// CheckVowelConsonantStringIndexOf
import java.util.Scanner;

// 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: Define a string containing all vowels (both cases)
        String vowels = "aeiouAEIOU";

        // Step 5: Check if the character exists in the vowels string
        // indexOf() returns the index of the character if found, -1 otherwise.
        if (vowels.indexOf(ch) != -1) {
            System.out.println(ch + " is a Vowel.");
        } else {
            System.out.println(ch + " is a Consonant.");
        }

        // Step 6: Close the scanner
        scanner.close();
    }
}