using System;

public class Program

{

    public static void Main()

    {

        var a = default(string);

        var b = "";

        var c = "value";

        Console.WriteLine($"Test 1: {(a == "" ? "": a + "-end")}");//should be blank !!!

        Console.WriteLine($"Test 2: {(b == "" ? "": b + "-end")}");//should be blank

        Console.WriteLine($"Test 3: {(c == "" ? "": c + "-end")}");//should not be blank

​

        Console.WriteLine($"Test 4: {(string.IsNullOrWhiteSpace(a) ? "": a + "-end")}");//should be blank

        Console.WriteLine($"Test 5: {(string.IsNullOrWhiteSpace(b) ? "": b + "-end")}");//should be blank

        Console.WriteLine($"Test 6: {(string.IsNullOrWhiteSpace(c) ? "": c + "-end")}");//should not be blank

    }

}