GetLimitedString

using System;
using System.Text;

//06. Write a program that reads from the console a string of maximum 20 characters.
//If the length of the string is less than 20, the rest of the characters should
//be filled with '*'. Print the result string into the console.

internal class GetLimitedString
{
    private static void Main()
    {
        int strLength = 20;
        StringBuilder str = new StringBuilder("", strLength);
        string userInput = "";
        while (true)
        {
            Console.Write("\nEnter a string of maximum {0} characters: ", strLength);
            userInput = Console.ReadLine();
            if (userInput.Length <= strLength)
            {
                break;
            }
            Console.WriteLine("Invalid input! Please try again...");
        }
        str.Append(userInput);
        for (int i = userInput.Length; i < strLength; i++)
        {
            str.Append("*");
        }
        userInput = str.ToString();
        Console.WriteLine(userInput);
    }
}