C# Nullable arrays

arrays, c#, nullable

Solution

Arrays are always reference types, as is `string` - so they're already nullable. You only need to use (and only can use) `Nullable<T>` where T is a non-nullable value type.

So you probably want:

public ActionResult Search(string searchString, int[] locationIds,
                           DateTime? startDate,  DateTime? endDate)

Note that I've changed your parameter names to follow .NET naming conventions, and changed `LocationId` to `locationIds` to indicate that it's for multiple locations.

You might also want to consider changing the parameter type to `IList<int>` or even `IEnumerable<int>` to be more general, e.g.

public ActionResult Search(string searchString, IList<int> locationIds,
                           DateTime? startDate,  DateTime? endDate)

That way a caller could pass in a `List<int>` for example.

Problem

I have a search function, but I would like `LocationID` to be an array of integers rather than just a single integer. I'm not sure how to do this since I want it to also be nullable. I've looked at doing `int?[]` but then I'd have to check the `HasValue` of every single entry. Is there a better way? This is what I currently have: ``` public ActionResult Search(string? SearchString, int? LocationId, DateTime? StartDate, DateTime? EndDate) ```

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