If, Symbols - C# Programming Exercise

using System;  // Import the System namespace to use basic classes like Console

class Program  // Define the main class of the program
{
    static void Main()  // The entry point of the program
    {
        // Ask the user to enter a symbol
        Console.Write("Enter a symbol: ");  // Display prompt for the symbol input
        char symbol = Console.ReadKey().KeyChar;  // Read the symbol entered by the user

        // Check if the symbol is an uppercase vowel
        if ("AEIOU".IndexOf(symbol) >= 0)  // If the symbol is in the string "AEIOU"
        {
            Console.WriteLine("\nThe symbol is an uppercase vowel.");  // Display message for uppercase vowel
        }
        // Check if the symbol is a lowercase vowel
        else if ("aeiou".IndexOf(symbol) >= 0)  // If the symbol is in the string "aeiou"
        {
            Console.WriteLine("\nThe symbol is a lowercase vowel.");  // Display message for lowercase vowel
        }
        // Check if the symbol is a digit
        else if (Char.IsDigit(symbol))  // If the symbol is a digit
        {
            Console.WriteLine("\nThe symbol is a digit.");  // Display message for digit
        }
        // If none of the above conditions are true, it's any other symbol
        else
        {
            Console.WriteLine("\nThe symbol is neither a vowel nor a digit.");  // Display message for other symbols
        }
    }
}