Regex.Replace, String.Replace or StringBuilder.Replace which is the fastest?

Question

I need to replace all System.Environment.Newline(s) in the string returned by my function with System.Environment.Newline + \t (as I am trying to apply indenting) and I need to do this several times.

My question is which one is the most efficient way to do this?

I know that StringBuilder is faster than String.Replace but I dont know about Regex.Replace.

Answer 1

If you're just trying to do it within a single string, I'd expect string.Replace to be as fast as anything else. StringBuilder is useful when you want to perform a number of separate steps and want to avoid creating an intermediate string on each step.

Have you benchmarked string.Replace to find out whether or not it's fast enough for you?

I would personally only start using regular expressions when I was actually dealing with a pattern, rather than just a fixed sequence of characters. If the performance of this is absolutely crucial, you could benchmark that as well of course.