using System;
using System.Collections.Generic;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            Iterate(CreateQueue(), "queue");
            Iterate(CreateStack(), "stack");

            Console.ReadKey();
        }

        private static IEnumerable<int> CreateQueue()
        {
            var collection = new Queue<int>();
            for (int i = 0; i < 4; i++)
                collection.Enqueue(i);
            return collection;
        }

        private static IEnumerable<int> CreateStack()
        {
            var collection = new Stack<int>();
            for (int i = 0; i < 4; i++)
                collection.Push(i);
            return collection;
        }

        private static void Iterate(IEnumerable<int> collection, string name)
        {
            Console.Write($"{name} foreach: ");
            foreach (var entry in collection)
                Console.Write($"{entry} ");
            Console.WriteLine();
        }
    }
}