How do I check whether my Generic List IsNullOrEmpty?

In this code snippet we will take a look, how we can implement IsNullOrEmpty() similar to String.IsNullOrEmpty() for our generic collections.

In my previous interview I have got one bumbarded question.

Q. Can I implement IsNullOrEmpty for my Generic collections/lists ?

Ans. Its out of C#. Unfortunately there is only one method which is of a String method String.IsNullOrEmpty() available, framework does not provide us such things.

What is the solution for this.

A solution is only Extension Method, we just need to create an Extension Method which will provide the same facility: Here is the extension method:

public static class CollectioncExtensionMethods
    {
        public static bool IsNullOrEmpty<T>(this IEnumerable<T> genericEnumerable)
        {
            return ((genericEnumerable == null) || (!genericEnumerable.Any()));
        }

        public static bool IsNullOrEmpty<T>(this ICollection<T> genericCollection)
        {
            if (genericCollection == null)
            {
                return true;
            }
            return genericCollection.Count < 1;
        }
    }

Enjoy the benefit of these extension methods :)

var serverDataList = new List<ServerData>();

var result = serverDataList.IsNullOrEmpty();//It will use IsNullOrEmpty<T>(this ICollection<T> gnericCollection)

var serverData = new ServerDataRepository().GetAll();

// It will use IsNullOrEmpty<T>(this IEnumerable<T> genericEnumerable)
var result = serverData.IsNullOrEmpty();

Can you think what it will give when I call serverDataList.Count and when I call serverData.Count ?

Hint: One will give me O(n) while other O(1), enjoy :)