Why does this regex with no special character match a longer string?

Question

I am using this method to try find a match, in an example:

Regex.Match(\"A2-TS-OIL\", \"TS-OIL\", RegexOptions.IgnoreCase).Success;

I got a tru

Answer 1

TS-OIL is a substring in your A2-TS-OIL. So, it would generate a match. You have the simplest match possible - literal substring. If you want TS-OIL to not match, you could also try (?!^A2-)(TS-OIL), assuming that you don't want it to start with A2-, but other things might be desired.