using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        SimpleClosures();

        //ChangedVariable();

        //Copy();

        //LongLived();

    }

    public static void SimpleClosures()

    {

        int age = 20;

        Func<int, int> getOlderOn = x => age + x;

        Console.WriteLine(getOlderOn(12));

    }

    public static void ChangedVariable()

    {

        int nonLocalVariable = 1;

        Func<int> add = () =>

        {

            int localVariable = 1;

            return localVariable + nonLocalVariable;

        };

        nonLocalVariable = 3;

        int result = add(); 

        Console.WriteLine(result);

    }

    public static void Copy()

    {

        List<Func<int>> functions = new List<Func<int>>(3);

        for (int nonLocalVariable = 0; nonLocalVariable < 3; nonLocalVariable++)

        {

            Func<int> function = () => nonLocalVariable;

            functions.Add(function);

        }

        foreach (Func<int> function in functions)

        {

            int result = function();

            //Console.WriteLine(result);

        }

    }

    private static Func<int> longLifeFunction;

    public static void LongLived()

    {

        byte[] shortLifeVariable = new byte[5000000];

        longLifeFunction = () =>

        {

            byte value = shortLifeVariable[0];

            return 0;

        };

    }

}