using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var people = new[]

        {

            new

            {

                Name = "Vernon",

                Gender = "Male",

            },

                new

            {

                Name = "Carrie",

                Gender = "Female"

            },

                new

            {

                Name = "Thomas",

                Gender = "Male"

            }

        };

        // Method 1:

        var peopleByGender = people.GroupBy(arg => arg.Gender)

            .Select(x => new { Gender = x.Key, People = x });

​

        foreach (var genderGroup in peopleByGender)

        {

            Console.WriteLine(genderGroup.Gender);

            foreach (var person in genderGroup.People)

            {

                Console.WriteLine("  " + person.Name);

            }

        }

​

    }

}