Data (Adult, Person, Family ) Console-App cool example

// Adult------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Data
{
    public class Adult : Person
    {
        public string LicenseNumber { get; set; }
        public string Job { get; set; }

        public override string ToString()
        {
            //return string.Format("{0} - {1}, {2}, LicenseNumber = {3}", Name, Age, Job, LicenseNumber);

            var famNm = $"{Name} - {Age},{Job}, LicenseNumber = {LicenseNumber}";

            return famNm; 
        }

    }
}

//Person------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Data
{
    public class Person
    { 
        public int PersonId { get; set; }
        public string Name { get; set; }
        public DateTime DateOfBirth { get; set; }

        public int Age
        {
            get
            {
                return DateTime.Now.Year - DateOfBirth.Year;
            }
        }        
            
    }
}
//Family----------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Data
{
    public class Family
    {
        public int FamilyId { get; set; }
        public string Nickname { get; set; }
        public Adult Father { get; set; }
        public Adult Mother { get; set; }
        public List<Person> Children { get; set; }



        public Person YoungestChild
        {
            get
            {
                Person Youngest = null;
                int currMinAge = 999;
                if (Children != null)
                {
                    foreach (var person in Children)
                    {
                        if (person.Age < currMinAge)
                        {
                            Youngest = person;
                            currMinAge = person.Age;
                        }
                    }
                }
                return Youngest;
            }
        }


        public bool IsNice
        {
            get
            {                                                           // Makes it Lower Case
                var isParentsNice = Father.Name.StartsWith("o", StringComparison.CurrentCultureIgnoreCase)
                    || Mother.Name.StartsWith("O", StringComparison.CurrentCultureIgnoreCase);
                if (isParentsNice)
                {
                    return true;
                }
                if (Children != null)
                {
                    foreach (var kids in Children)
                    {
                        bool isNiceKid = kids.Name.StartsWith("o", StringComparison.CurrentCultureIgnoreCase);
                        if (isNiceKid) return true;
                    }
                }
                return false;
            }
        }

        public override string ToString()
        {
            var builder = new StringBuilder();

            builder.AppendLine(Nickname);
            builder.AppendLine("Parents:");
            builder.AppendLine(Father.ToString());
            builder.AppendLine(Mother.ToString());

            if (Children != null && Children.Count > 0)
            {
                builder.AppendLine("Kids:");

                foreach (var kid in Children)
                {
                    builder.AppendFormat("{0}-{1} \n", kid.Name, kid.Age);
                }
            }
            return builder.ToString();

            //return string.Format("{0}({1})", Nickname, FamilyId);
        }

        public Person OldestChild
        {
            get
            {
                Person Oldest = null;
                int currMaxAge = 0;
                if (Children != null)
                {
                    foreach (var person in Children)
                    {
                        if (person.Age > currMaxAge)
                        {
                            Oldest = person;
                            currMaxAge = person.Age;
                        }
                    }
                }
                return Oldest;
            }
        }
    }
}
//FamilyContext-----Used as DataBase------------------------
using Data;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Loops.Context
{
    public class FamilyContext
    {
        List<Family> _families = new List<Family>();

        public FamilyContext()
        {
            var family1 = new Family()
            {
                FamilyId = 1,
                Nickname = "Family One ",
                Father = new Adult() { Name = "Jim", DateOfBirth = DateTime.Now.AddYears(-34), Job = "Programmer", LicenseNumber = "2344454", PersonId = 5 },
                Mother = new Adult() { Name = "Amy", DateOfBirth = DateTime.Now.AddYears(-33), Job = "Accountant", LicenseNumber = "8888", PersonId = 6 },
                Children = new List<Person>()
                 {
                   new Person() {Name = "Bob",DateOfBirth = DateTime.Now.AddYears(-4),PersonId = 1},
                   new Person() {Name = "Ella",DateOfBirth = DateTime.Now.AddYears(-6),PersonId = 2},
                   new Person() {Name = "Sophia",DateOfBirth = DateTime.Now.AddYears(-3),PersonId = 3},
                 }
            };
            _families.Add(family1);



            var family2 = new Family()
            {
                FamilyId = 2,
                Nickname = "Family two ",
                Father = new Adult() { Name = "Noah", DateOfBirth = DateTime.Now.AddYears(-28), Job = "Plumber", LicenseNumber = "12344454", PersonId = 15 },
                Mother = new Adult() { Name = "Emma", DateOfBirth = DateTime.Now.AddYears(-25), Job = "Homemaker", LicenseNumber = "18888", PersonId = 16 },
                Children = new List<Person>()
                 {
                   new Person() {Name = "Matthew",DateOfBirth = DateTime.Now.AddYears(-10),PersonId = 11},
                   new Person() {Name = "James",DateOfBirth = DateTime.Now.AddYears(-7),PersonId = 13},
                 }
            };
            _families.Add(family2);



            var family3 = new Family()
            {
                FamilyId = 3,
                Nickname = "Family three ",
                Father = new Adult() { Name = "Bill", DateOfBirth = DateTime.Now.AddYears(-25), Job = "Driver", LicenseNumber = "12344454", PersonId = 35 },
                Mother = new Adult() { Name = "Judy", DateOfBirth = DateTime.Now.AddYears(-23), Job = "Teacher", LicenseNumber = "18888", PersonId = 36 },
            };
            _families.Add(family3);



            var family4 = new Family()
            {
                FamilyId = 4,
                Nickname = "Family four",
                Father = new Adult() { Name = "Orest", DateOfBirth = DateTime.Now.AddYears(-28), Job = "Architect ", LicenseNumber = "2344454", PersonId = 45 },
                Mother = new Adult() { Name = "Lena", DateOfBirth = DateTime.Now.AddYears(-27), Job = "Accountant", LicenseNumber = "8888", PersonId = 46 },
                Children = new List<Person>()
                 {
                   new Person() {Name = "Alexis",DateOfBirth =new DateTime(2008,10,21),PersonId = 41},
                   new Person() {Name = "Ella",DateOfBirth = new DateTime(2004,8,16),PersonId =42},
                 }
            };
            _families.Add(family4);
        }



        public List<Family> Families
        {
            get { return _families; }
        }
    }
}
// FamilyStatistics------Used as Business Logic----------------
using Loops.Context;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Data
{
    public class FamilyStatistics
    {
        private List<Family> _families = new List<Family>();
        public FamilyStatistics()
        {
            var context = new FamilyContext();
            _families = context.Families;
        }

        public List<Family> GetByParentName(string name)
        {
            var fams = new List<Family>();
            foreach (var Family in _families)
            {                                       //does not metter Later-Case it will be found by name
                if (Family.Father.Name.Equals(name, StringComparison.CurrentCultureIgnoreCase) // Makes it Lower Case
                    || Family.Mother.Name.Equals(name, StringComparison.CurrentCultureIgnoreCase))
                {
                    fams.Add(Family);
                }
            }
            return fams;
        }

        public List<Family> GetNiceFamilies()
        {
            var returnFamilies = new List<Family>();
            foreach (var Family in _families)
            {
                if (Family.IsNice)
                {
                    returnFamilies.Add(Family);
                }
            }
            return returnFamilies;
        }


        public List<Family> GetFamilyWithNoKid()
        {
            var returnFamilies = new List<Family>();
            foreach (var Family in _families)
            {
                if (Family.Children == null)
                {
                    returnFamilies.Add(Family);
                }
            }
            return returnFamilies; 
        }


        public List<Family> GetFamilywithYongest()
        {
            var returnFamilies = new List<Family>();
            int CurrMinAge = 999;
            foreach (var Family in _families)
            {
                if (Family.Children != null)
                {
                    if (Family.YoungestChild.Age < CurrMinAge)
                    {
                        CurrMinAge = Family.YoungestChild.Age;
                    }
                }
            }
            foreach (var family in _families)
            {
                if (family.Children != null)
                {
                    if (family.YoungestChild.Age == CurrMinAge)
                    {
                        {
                            returnFamilies.Add(family);
                        }
                    }
                }
            }
            return returnFamilies;
        }

        public List<Family> GetFamilywithOldest()
        {
            var returnFamily = new List<Family>();
            int CurrMaxAge = 0; 
            foreach (var Family in _families)
            {
                if (Family.Children != null)
                {
                    if (Family.OldestChild.Age > CurrMaxAge)
                    {
                        CurrMaxAge = Family.OldestChild.Age;
                    }
                }
                foreach (var family in _families)
                {
                    if (family.Children !=null)
                    {
                        if (family.OldestChild.Age == CurrMaxAge)
                        {
                            returnFamily.Add(family);
                        }
                    }
                }
            }
            return returnFamily;
        }
    }
}
//Program------Calling Methods-------------------------------------------------------
using Loops.Context;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Data
{
    class Program
    {
        static void Main(string[] args)
        {
            var context = new FamilyContext();
            var families = context.Families;
            //PrintFamily(families);  //call all the families
            Console.WriteLine(families.Count);

            FamilyStatistics stats = new FamilyStatistics();
            //PrintFamily(stats.GetByParentName("emma")); // call family by children name           
            //PrintFamily(stats.GetNiceFamilies());  // Logic to choose Nice Families
            //PrintFamily(stats.GetFamilyWithNoKid());  // Family With out Children
            //PrintFamily(stats.GetFamilywithYongest()); // get Family with Youngest child
            PrintFamily(stats.GetFamilywithOldest());  // Get family with Oldest child



            Console.ReadLine();
        }

        private static bool PrintFamily(List<Family> families)
        {

            foreach (var family in families)
            {
                Console.WriteLine(family.ToString());
                Console.WriteLine("--------------");
            }
            return true;
        }


    }
}

//Display info about families. >
//Family with most kids. >
//Family with no Kids. >
//Youngest Child. >
//Oldest Child. >
//Family father name. +
//Youngest Family +
//Family where Parent Name starts with "o" +
//find Awesome family (if any name starts with "o") +