Regex word boundary expressions

Question

Say for example I have the following string \"one two(three) (three) four five\" and I want to replace \"(three)\" with \"(four)\" but

Answer 1

As Gopi said, but (theoretically) catching only (three) not two(three):

string input = "one two(three) (three) four five";

string output = input.Replace(" (three) ", " (four) ");

When I test that, I get: "one two(three) (four) four five" Just remember that white-space is a string character, too, so it can also be replaced. If I did this:

//use same input
string output = input.Replace(" ", ";");

I'd get one;two(three);(three);four;five"