Best way to check for string in comma-delimited list with .NET?

Question

I\'m reading a comma-delimited list of strings from a config file. I need to check whether another string is in that list. For example:

\"apple,banana,cheese\"

Answer 1

Using linq:

listString.Split(',').Contains("apple")

W/o linq:

Array.IndexOf(listString.Split(','), "apple") >= 0

Answer 2

This works, but regexes are pretty slow if they get complicated. That said, the word boundary anchor makes this sort of thing pretty easy.

var foods = "apple,banana,cheese";

var match = Regex.Match(foods, @"\bapple\b");

if (match.Success)
    Console.WriteLine(match.Value);

Answer 3

This is solution for ignoring case and culture(or select one of the property of StringComparer)

var commaDelimitedString = "string1,string2,string3,string4";
var testString = string2.trim; // trim to remove the spaces coz you may be getting it from UI
if(commaDelimitedString.split(',').contains(testString,StringComparer.InvariantCultureIgnoreCase))
{
     //TODO: What to do when condition is true
}
else
{
     //TODO: What to do when condition is false
}