How to make IEnumerable.Contains case-insensitive?

Question

Suppose I have a .net Array of strings.

string[] strings = new string[] { \"AbC\", \"123\", \"Xyz\", \"321\" };

If I wanted to see if the a

Answer 1

Use overloaded Enumerable.Contains method which accepts equality comparer:

strings.Contains("ABC", StringComparer.InvariantCultureIgnoreCase)

Also there is strings comparer in box which you can use.