C#_OOP_2b_Manager.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace OOP9
{
    class Manager<T>
    {
        private const int LIMIT = 5;
        T[] entities;
        private int counter;

        public Manager()
            : this(LIMIT)
        {}

        public Manager(int limit)
        {
            entities = new T[limit];
            counter = 0;
        }

        public void Add(T entity)
        {
            if (counter >= entities.Length)
            {
                throw new InvalidOperationException("The limit has been reached");
            }
            entities[counter] = entity;
            counter++;
        }

        public T Remove()
        {
            if (counter == 0)
            {
                throw new InvalidOperationException("No entities");
            }
            T temp = entities[counter - 1];
            entities[counter - 1] = default(T);
            counter--;
            return temp;
        }

        public int GetNumberOfEntities()
        {
            return counter;
        }
    }
}