public void Enqueue(LinkedQueueItem <T> item)
{
if (item == null)
{
throw new ArgumentNullException("Cannot add null items.");
}
if (this.EnqueuedInstances.Contains(item))
{
throw new InvalidOperationException("Instance already added.");
}
if (this.FirstItem == null)
{
this.FirstItem = item;
this.LastItem = item;
}
else
{
this.LastItem.NextItem = item;
}
this.EnqueuedInstances.Add(item);
}
private static void Main()
{
var first = new LinkedQueueItem <int>(1);
var sec = new LinkedQueueItem <int>(2);
var q = new LinkedQueue <int>();
try
{
Console.WriteLine(q.Dequeue());
}
catch (InvalidOperationException e)
{
Console.WriteLine(e.Message);
}
Console.WriteLine("-----Enqueuing 1");
q.Enqueue(first);
Console.WriteLine("-----Dequeuing");
Console.WriteLine(q.Dequeue().Value);
Console.WriteLine("-----Enqueuing value 1");
q.Enqueue(first);
Console.WriteLine("-----Enqueuing value 2");
q.Enqueue(sec);
Console.WriteLine("-----Dequeuing");
Console.WriteLine(q.Dequeue().Value);
Console.WriteLine("-----Dequeuing");
Console.WriteLine(q.Dequeue().Value);
Console.WriteLine("-----Dequeuing");
try
{
Console.WriteLine(q.Dequeue());
}
catch (InvalidOperationException e)
{
Console.WriteLine(e.Message);
}
Console.WriteLine("-----Enqueuing value 1");
q.Enqueue(first);
try
{
Console.WriteLine("-----Enqueuing value 1");
q.Enqueue(first);
}
catch (InvalidOperationException e)
{
Console.WriteLine(e.Message);
}
try
{
Console.WriteLine("-----Enqueuing null");
q.Enqueue(null);
}
catch (ArgumentNullException e)
{
Console.WriteLine(e.Message);
}
}
