Is there a way to get the last element in a Queue?

Question

I know stack is best and easiest way, yet could it be possible to obtain the last element in a queue without having to dequeue anything?

Answer 1

If you really need to you can use this but consider using a different data structure:

public static class QueueExtensions
{
    const BindingFlags _flags = 
        BindingFlags.NonPublic | BindingFlags.GetField | BindingFlags.Instance;

    private static readonly FieldInfo _array =
        typeof(Queue).GetField("_array", _flags);

    private static readonly FieldInfo _size = 
        typeof(Queue).GetField("_size", _flags);

    public T LastItem(this Queue value)
    {
        if (value == null) 
            throw new ArgumentNullException("value");
        if (value.Count == 0) 
            throw new ArgumentException("The queue cannot be empty.", "value");
        var array = (T[])_array.GetValue(value);
        var size = (int)_size.GetValue(value);
        return array[size - 1];
    }
}