using System;

using System.Reflection;

​

public class Program

{

    public static void Main()

    {

        var p = new Person{FirstName = "John", LastName = "Doe"};

        p.Validate();

    }

}

​

public class Person

{

    private string _test

    {

        get;

        set;

    }

​

    public string FirstName

    {

        get;

        set;

    }

​

    public string LastName

    {

        get;

        set;

    }

​

    public string TelephoneNumber

    {

        get;

        set;

    }

​

    public void Validate()

    {

        var properties = GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance);

        foreach (var property in properties)

        {

            var value = property.GetValue(this);

            if (value != null)

            {

                Console.WriteLine(property.Name + " " + value.ToString());

            }

​

            if (value == null)

            {

                Console.WriteLine(property.Name + " cannot be null");

            }

        }

    }

}