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IsNullOrEmpty for Generic Collections in C#

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12 Aug 2015CPOL 33.7K   11   22
IsNullOrEmpty for Generic Collections in C#

In this code snippet, we will see the creation and implementation of IsNullOrEmpty for collections.

Can I Implement IsNullOrEmpty for my Generic Collections/Lists?

It's 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 an Extension Method, we just need to create an Extension Method which will provide the same facility: Here is the extension method:

C#
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. :)

C#
var serverDataList = new List<ServerData>();  

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

If still confused, view this video on .NET collection by legend author, Mr. Shivprasad Koirala.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


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Comments and Discussions

 
GeneralMy vote of 5 Pin
D V L23-Aug-15 19:55
professionalD V L23-Aug-15 19:55 
AnswerRe: My vote of 5 Pin
Gaurav Aroraa23-Aug-15 21:56
professionalGaurav Aroraa23-Aug-15 21:56 
QuestionNot really a good idea Pin
William E. Kempf13-Aug-15 6:01
William E. Kempf13-Aug-15 6:01 
AnswerRe: Not really a good idea Pin
mtiede13-Aug-15 10:50
mtiede13-Aug-15 10:50 
GeneralRe: Not really a good idea Pin
codefabricator18-Aug-15 5:55
codefabricator18-Aug-15 5:55 
QuestionNice trick Pin
DotNetForAll13-Aug-15 3:57
DotNetForAll13-Aug-15 3:57 
AnswerRe: Nice trick Pin
Gaurav Aroraa13-Aug-15 4:00
professionalGaurav Aroraa13-Aug-15 4:00 
QuestionGreat Pin
irneb13-Aug-15 2:13
irneb13-Aug-15 2:13 
AnswerRe: Great Pin
Gaurav Aroraa13-Aug-15 3:53
professionalGaurav Aroraa13-Aug-15 3:53 
First of all thanks for your great words. It opens many doors to do research for me.
I believe many of them are in this sentence:
Hint: One will give me O(n) while other O(1), enjoy

irneb wrote:
Just a query re collection-vs-enumerable in extension methods: I know there's some issues with extension methods when working with polymorphic overrides. Have you actually debug stepped through your code to see if the "correct" variant is called on collections (i.e. a collection is also an enumerable)?

Yes, I debug, unfortunately for large collection I can't get in depth using VS2013, I will try on VS2015.

irneb wrote:
I'm definitely in agreement that you should not use "Count" on an enumerable to test if it's empty - that's just plain "silly".


Absolutely, correct!

irneb wrote:
But how much faster is testing Count on a collection vs. the Any() function on an enumerable?


Need to perform some kind of Load testing, will try to add more content to this post, later this weekend.

irneb wrote:
Perhaps you could just as well consolidate both those by simply omitting the collection version. Of course depending on if the performance hit on Any-vs-Count is not big enough to make much difference.


I would prefer either one is more performance.

Please share your thoughts, I will definitely try to make some kind of load testing for both scenarios.

@Mahsa-Hassankashi - can also provide some light on this. As she has already did few examples on collections.


modified 13-Aug-15 10:33am.

GeneralRe: Great Pin
irneb13-Aug-15 19:59
irneb13-Aug-15 19:59 
GeneralRe: Great Pin
Gaurav Aroraa13-Aug-15 20:11
professionalGaurav Aroraa13-Aug-15 20:11 
GeneralRe: Great Pin
irneb14-Aug-15 22:55
irneb14-Aug-15 22:55 
AnswerRe: Great Pin
Gaurav Aroraa15-Aug-15 22:49
professionalGaurav Aroraa15-Aug-15 22:49 
GeneralRe: Great Pin
irneb16-Aug-15 23:46
irneb16-Aug-15 23:46 
AnswerRe: Great Pin
Gaurav Aroraa17-Aug-15 1:18
professionalGaurav Aroraa17-Aug-15 1:18 
GeneralRe: Great Pin
irneb17-Aug-15 4:48
irneb17-Aug-15 4:48 
AnswerRe: Great Pin
Gaurav Aroraa17-Aug-15 22:37
professionalGaurav Aroraa17-Aug-15 22:37 
GeneralRe: Great Pin
Gaurav Aroraa24-Aug-15 5:29
professionalGaurav Aroraa24-Aug-15 5:29 
GeneralMy vote 5 Pin
Shuby Arora12-Aug-15 10:56
Shuby Arora12-Aug-15 10:56 
GeneralRe: My vote 5 Pin
Gaurav Aroraa13-Aug-15 3:53
professionalGaurav Aroraa13-Aug-15 3:53 

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