using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        int[] collect = new int[]{1,-1,0,2,5,-4};

        var result = collect.Filter(c=> c > 0).ToArray();       

        foreach(var item in result)

        {

            Console.WriteLine(item);

        }

    }

}

​

public static class Filtrating

{

    public delegate bool IsEqual(int x);

    public static IEnumerable<int> Filter(this IEnumerable<int> source, IsEqual func)

    {

        IEnumerable<int> collect = from i in source

            where func(i)

            select i;

        return collect;

    }

}