What is the linq equivalent to the SQL IN operator

Question

With linq I have to check if a value of a row is present in an array.
The equivalent of the sql query:

WHERE ID IN (2,3,4,5)

How can I

Answer 1

Perform the equivalent of an SQL IN with IEnumerable.Contains().

var idlist = new int[] { 2, 3, 4, 5 };

var result = from x in source
          where idlist.Contains(x.Id)
          select x;