Question

Given strings like these:

string s1 = "Abc";
string s2 = "ABC";

What is faster:

Regex.Match(s1, s2, RegexOptions.IgnoreCase)

or

s1.ToLower() == s2.ToLower()

If they are the same or the one is faster then the other, so when its better to use one over the other?

Answer 1

Probably the second is faster, but I’d avoid both those approaches.

Better is to use the method string.Equals with the appropriate StringComparison argument:

s1.Equals(s2, StringComparison.CurrentCultureIgnoreCase)

See it working online: ideone