Is there a C# IN operator?

Question

In SQL, you can use the following syntax:

SELECT * FROM MY_TABLE WHERE VALUE_1 IN (1, 2, 3) 

Is there an equivalent in C#? The IDE seems to recognise "in" as a keyword, but I don't seem to be able to find any information on it.

So, is it possible to do something like the following:

int myValue = 1; if (myValue in (1, 2, 3))     // Do something 

Instead of

int myValue = 1; if (myValue == 1 || myValue == 2 || myValue == 3)     // Do something 

Answer 1

If you wanted to write .In then you could create an extension that allows you to do that.

static class Extensions {      public static bool In<T>(this T item, params T[] items)     {         if (items == null)             throw new ArgumentNullException("items");          return items.Contains(item);     }  }   class Program {      static void Main()     {           int myValue = 1;          if (myValue.In(1, 2, 3))             // Do Somthing...          string ds = "Bob";          if (ds.In("andy", "joel", "matt"))          // Do Someting...     } } 

Answer 2

List.Contains() is I think what you're looking for. C# has in keyword and not an operator which serves completely different purpose then what you're referring in SQL.

There are two ways you can use in keyword in C#. Assume you have a string[] or List in C#.

        string[] names; //assume there are some names;          //find all names that start with "a"         var results = from str in names                       where str.StartsWith("a")                       select str;          //iterate through all names in results and print         foreach (string name in results)         {             Console.WriteLine(name);         } 

Referring your edit, I'd put your code this way to do what you need.

        int myValue = 1;         List<int> checkValues = new List<int> { 1, 2, 3 };          if (checkValues.Contains(myValue))             // Do something