// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002143/string-iscontrol

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        string input = "EF\nEF6\n\r";

​

        Console.WriteLine("{0}:\t{1}", "Index", "Is Control");

​

        for (int i = 0; i < input.Length; i++)

        {

            // C# Extension Method: String - IsControl

            var result = input.IsControl(i);

            Console.WriteLine("{0}:\t\t{1}", i, result);

        }

    }

}