C# lambda - small question

Question

Hello,

Need I here ToString() override?
Why can't I debug this? I can't get into GetAge.

//~~~~~

      public void Test()
            {

                User[] users =
                    {
                  new User (1, "John", "London", "2001-04-01"),
                  new User(2, "Lenny", "New York", "1997-12-11"),
                  new User(3, "Andrew", "Boston", "1987-02-22"),
                  new User(4, "Peter", "Prague", "1936-03-24"),
                  new User(5, "Anna", "Bratislava", "1973-11-18"),
                  new User(6, "Albert", "Bratislava", "1940-12-11"),
                  new User(7, "Adam", "Trnava", "1983-12-01"),
                  new User(8, "Robert", "Bratislava", "1935-05-15"),
                  new User(9, "Robert", "Prague", "1998-03-14")
                };

                var country = "Bratislava";
                Func<User, bool> livesIn = e => e.Country == country;

                var res = users.Where(livesIn);

                foreach (var e in res)
                {
                    Console.WriteLine(e);
                }


                var users2 = new List<User>
                        {
                          new User(1, "John", "London", "2001-04-01"),
                          new User(2, "Lenny", "New York", "1997-12-11"),
                          new User(3, "Andrew", "Boston", "1987-02-22"),
                          new User(4, "Peter", "Prague", "1936-03-24"),
                          new User (5, "Anna", "Bratislava", "1973-11-18"),
                          new User (6, "Albert", "Bratislava", "1940-12-11"),
                          new User(7, "Adam", "Trnava", "1983-12-01"),
                          new User (8, "Robert", "Bratislava", "1935-05-15"),
                          new User(9, "Robert", "Prague", "1998-03-14"),
                        };

                var age2 = 60;
                Func<User, bool> olderThan = e => GetAge(e) > age2;

                var res2 = users.Where(olderThan);

                foreach (var e in res)
                {
                    Console.WriteLine(e);
// Need I here ToString() override?
                }

            }

//Why can't I debug this? I can't get into GetAge.

      int GetAge(User user)
            {
                var dob = DateTime.Parse(user.Birthday);
                return (int)Math.Floor((DateTime.Now - dob).TotalDays / 365.25D);
            }

Answer 1

Here is a simple example done in a console project.

The console project uses two class project, BaseDataValidatorLibrary for validating models and uses System.ComponentModel.Annotations NuGet package, The second class project, BaseModelsLibrary has various models to validate.

If this works for you, clone the repository, all you need is the BaseDataValidatorLibrary class project.

Here is the example from my first reply in a console project.

using System;  
using BaseDataValidatorLibrary.Helpers;  
using BaseModelsLibrary.Models;  
using static System.DateTime;  
  
namespace PersonValidationConsole  
{  
    class Program  
    {  
        static void Main(string[] args)  
        {  
            PersonIsValid();  
            Console.WriteLine();  
            PersonIsNotValid();  
              
            Console.ReadLine();  
        }  
  
        private static void PersonIsNotValid()  
        {  
            Title(nameof(PersonIsNotValid));  
            Person person = Person;  
            person.BirthDate = new DateTime(1931, Now.Month, Now.Day);  
  
            EntityValidationResult result = Model.Validate(person);  
  
            if (result.IsValid)  
            {  
                Console.WriteLine("Valid");  
            }  
            else  
            {  
                foreach (var error in result.Errors)  
                {  
                    Console.WriteLine(error.ErrorMessage);  
                }  
            }  
        }  
  
        private static void PersonIsValid()  
        {  
            Title(nameof(PersonIsValid));  
            Person person = Person;  
              
            EntityValidationResult result = Model.Validate(person);  
  
            if (result.IsValid)  
            {  
                Console.WriteLine("Valid");  
            }  
            else  
            {  
                foreach (var error in result.Errors)  
                {  
                    Console.WriteLine(error.ErrorMessage);  
                }  
            }  
        }  
  
        private static Person Person => new()  
        {  
            FirstName = "Mike",  
            LastName = "Flowers",  
            BirthDate = new DateTime(1932, Now.Month, Now.Day)  
        };  
  
        private static void Title(string sender)  
        {  
            Console.ForegroundColor = ConsoleColor.White;  
            Console.Write("Running");  
            Console.ResetColor();  
            Console.Write($" {sender}\n");  
        }  
    }  
}  
  

Note that there are a good deal of code samples in the repository to learn from, most are done in unit test and one in ASP.NET Core Razor.

Answer 2

There is no built in tools to debug into your method. Best recommendation is to use LINQPad and use it's Dump method or OzCode.