C# lambda expression

/////////////////////// array.Sort
 var arr = new[]
            {
                new{X = 3, Y = 5},
                new{X = 3, Y = 6},
                new{X = 33, Y = 5},
                new{X = 34, Y = 55},
                new{X = 333, Y = 54},
                new{X = 33, Y = 6},
                new{X = 13, Y = 5},
                new{X = 21, Y = 16},
            };


            Array.Sort(arr,
                (a, b) => -a.Y.CompareTo(b.Y) == 0 ?
                a.X.CompareTo(b.X) :
                -a.Y.CompareTo(b.Y)
                );

            foreach (var item in arr)
            {
                Console.WriteLine(item);
            }

            Console.WriteLine();
            Console.WriteLine();

            Array.Sort(arr, (a, b) =>
                  {
                      if (a.Y == b.Y)
                      {
                         return a.X.CompareTo(b.X);
                      }
                      else
                      {
                         return a.Y.CompareTo(b.Y);
                      }
                  }
                  );

            foreach (var item in arr)
            {
                Console.WriteLine(item);
            }

////////////////////// find all vsi4kite chetni chisla  ///////////////////////



 List<int> list = new List<int>() { 1, 2, 3, 4 };
            List<int> evenNumbers = list.FindAll(x => (x % 2) == 0);
            foreach (var num in evenNumbers)
            {
                Console.Write("{0} ", num);
            }
            Console.WriteLine();
            // 2 4


///////////////////////  remove all  po-golemi ot 6   ///////////////////////////////////


            List<int> list = new List<int>() { 1, 2, 3, 4,5,6,7,8,9,0,12,-5 };

            list.RemoveAll(x => x > 6);
            foreach (var num in list)
            {
                Console.Write("{0} ", num);
            }
            Console.WriteLine();
            // 1 2 3


/////////////////////// OrderBy  pets po godini moje i po imena  v azbuchen red ////////////////////////


    class Pet
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }


        static void Main(string[] args)
        {

        var pets = new Pet[]
        {
          new Pet { Name="Sharo", Age=8 },
          new Pet { Name="Rex", Age=4 },
          new Pet { Name="Strela", Age=1 },
          new Pet { Name="Bora", Age=3 }
        };
            var sortedPets = pets.OrderBy(pet => pet.Age);

            foreach (Pet pet in sortedPets)
            {
                Console.WriteLine("{0} -> {1}",
                  pet.Name, pet.Age);
            }


////////////// findAll   che moga vutre v lambda expresinite da si otvarqm { } skobi i da si pishe  algoritmi ////////


            list = new List<int>()
            { 20, 1, 4, 8, 9, 44 };

        // Process each argument with code statements
        evenNumbers = list.FindAll((i) =>
            {
                Console.WriteLine("value of i is: {0}", i);
                return (i % 2) == 0;
            });

        Console.WriteLine("Here are your even numbers:");
        foreach (int even in evenNumbers)
            Console.Write("{0} ", even);





//////////////////   funk bool   ////////////////////////////////////////////////

 Func<bool> boolFunc = () => true;
            Func<int, bool> intFunc = (x) => x < 10;
            if (boolFunc() && intFunc(5))
            {
                Console.WriteLine("5 < 10");
            }



/////////////////// finAll i davame delegate vsi4ki suvpadashti na 'S' i da gi natrupva vuv lista townsWithS ///////

  List<string> towns = new List<string>()
        {
          "Sofia", "Plovdiv", "Varna", "Sopot", "Silistra"
        };

            List<string> townsWithS =
              towns.FindAll(delegate(string town)
              {
                  return town.StartsWith("S");
              });

            // A short form of the above (with lambda expression)
            //List<string> townsWithS = towns.FindAll((town) => town.StartsWith("S"));

            foreach (string town in townsWithS)
            {
                Console.WriteLine(town);
            }