How to check if the list is empty before using Select(LINQ)?

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I’m using a dictionary and the key will be the property name and value will be the LINQ query below:

Model.Listexample.Select(a => a.property)

How I can check if there are any items in the list without writing if statement? We can use any other LINQ statement where it checks if there are any elements in the list before using Select().

I tried (Model.Listexample.Any()).Select but it didn’t work.

Don't check if the List is empty, the Select will do it for you. At most you can check for null:

var newList = Model.Listexample?.Select(a => a.property)

How to check if the list is empty before using Select(LINQ)?, How to check if the list is empty before using Select(LINQ)? - c# other LINQ statement where it checks if there are any elements in the list before using Select (). LINQ query operators and null lists 8 December, 2009. It was a Tuesday. One of my pet peeves with the LINQ extension methods is their inability to handle null source lists. For example, this will throw an ArgumentNullException: [Test] public void Should_handle_nulls() { List < int > ints = null; ints.Any(num => num < 0).ShouldBeFalse(); }

You can check to use below syntax in linq:

Model.Listexample?.Select(a => a.property)

Null or empty object when LINQ to Entities query returns nothing , Select(Mapper. ToList() after the where, before the any. If you really expect there could be multiple matches, then just return the list of matches. Now to the interesting question: What to return from a method which finds either a Disadvantages: The client have to check for null which is easily forgotten� Select is a LINQ functionality to define a data format of the query results.. Each of below examples is presented in C# with both Lambda and Query expression. Let’s create a Person class.

Model.Listexample.Any(a => a.property) ? Model.Listexample.Select(a => a.property) : null;

Is it unreasonable to expect Any() *not* to throw a null reference , But if you don't know that it exists, then it does make sense to check X DO NOT return null values from collection properties or from It throws an exception for an EMPTY list, shouldn't it throw also for a null one? What library designers did before LINQ was to introduce explicit methods when null is a valid� The where clause is only used to extract records from select, delete, update and so on. LINQ Where Clause Operator in Method Syntax. Following is the syntax of using LINQ where clause filtering operator in method syntax to get data from collection list based on conditions. C# Code

How to handle NULL object property with FirstOrDefault using Linq, Or else you can use ?. to check for null like this: string employee_name = employees.FirstOrDefault(a => a.EmployeeNumber == 20000)?. Any help would be appreciated, thanks. Tag: Windows Presentation Foundation (WPF) ComboBox Error: The items collection must be empty before using ItemsSource Visual Studio 2008; 7. Showing context menu other then right click Hi, I would really like to be able to programmatically display an objects (ListViewItem typically) context menu. I can

Enumerable.FirstOrDefault Method (System.Linq), Returns the first element of a sequence, or a default value if no element is found. An IEnumerable<T> to return an element from. default ( TSource ) if source is empty or if no element passes the test specified by List<int> months = new List <int> { }; // Setting the default value to 1 after the query. int firstMonth1 = months. So if in a single SP I need to do a select first- then an Update -then a Select again ,How can I do this in Linq To Sql Hope all clear. Thanks a lot in advance Tag: Windows Presentation Foundation (WPF) ComboBox Error: The items collection must be empty before using ItemsSource Visual Studio 2008

The 10 Most Common Mistakes in C# Programming, Rather, the preferred way to test for string equality in C# programming is with the Some C# programmers don't even know of LINQ's existence, but fortunately So for example, if you had an array of Accounts, instead of writing a C# List foreach: the capital A)? Well, if myAccounts was a DbSet object (that was set up with� Point accepted and thank you. However it is not about adopting a coding strategy. I agree there is a check needed to see if the string is empty before using this code. The article purely focuses on different ways to use the null-coalesce operator and I just showed one way. That extension method of yours is useful. August 25, 2010 at 2:26 AM

Comments
  • And how do you think Any() is written? What do you have against if() statements?
  • Hi Tanveer - I think it’s not good to use an if statement inside a dictionary object. As I mentioned above key is property name and value is Select LINQ statement, I want to use Any() and Select() in a same statement rather than using if statement again. Is it possible through LINQ?
  • @Stackoverflowuser - Could you please clarify your question as per the comments in the answers?
  • As commented, the OP does not need to check the list for nullity but for emptiness
  • @vc74 - The OP's question doesn't make sense if taken at face value - this answer is the best interpretation of the actual need in my opinion.
  • @Enigmativity IMO it's not, the OP has commented that the list is not null. He/she just want to have a different behavior in case the list is empty. Question is... which?
  • @Stackoverflowuser The point that I am trying to make in my answer is that the Select statement does check for Empty and returns an empty List. Is there something else that you want to do in that case?
  • @vc74 this sounds to me like an XY problem
  • Hi meJustAndrew and Bilal- I want to check if list has any items in it specifically it shouldn’t be an empty list like []. null check is already validated before in the code.
  • @Stackoverflowuser Which behavior (default value, exception...?) do you want when the list is empty?
  • @Stackoverflowuser Also, if you want to comment answers please do in the specific answers, not in other answers not related to your comment.
  • Is it correct ?Model.Listexample.Any(a => a.property) ? Model.Listexample.Select(a => a.property) : null;
  • @Stackoverflowuser It can be correct if a.property is a boolean, and you want to check if it's true for any item in the list but if you just want to check whether there are items in the list: Any() will do (check my answer)