How do you implement the equivalent of SQL IN() using .net

Question

In .net (c# or vb) expressions, how would you implement SQL\'s handy IN() functionality?

i.e. value in (1, 2, 4, 7)

rather than:

value = 1 or value =

Answer 1

If you will do many lookups on the same dataset it is good from a performance perspective to use HashSet.

HashSet numbers = new HashSet { 1, 2, 4, 7 };
bool is5inSet = numbers.Contains(5);