How can I replace specific word in c# with parenthesis?

Question

Consider the following string:

string s = "The man is (old).";

If I use:

Regex.Replace(s,@"\b\(old\)\b", @"<b>$&</b>");

The output is :
The man is (old).
But I would change the whole of the (old) word like this:
The man is (old).

How can I do this?

Philippe Leybaert · Accepted Answer · 2012-07-11T19:27:37.907

7

\b won't match because ( and ) are not word characters. Is there a reason why you put them there, because you could just leave them out:

 string replaced = Regex.Replace(s,@"\(old\)", @"<b>$&</b>");

According to the specs:

\b : The match must occur on a boundary between a \w (alphanumeric) and a \W (nonalphanumeric) character.

-space- and ) are both nonalphanumeric. The same for ( and ., so \b won't match in both cases.

edited Jul 11 '12 at 19:27

answered Jul 11 '12 at 18:32

Philippe Leybaert

I have a HTML Content and I have set the Multi line option in Regular Expression, but It doesn't work. – Houshang.Karami Jul 11 '12 at 19:16
You're right. The reason is that `(` and `)` are not word characters, so `\b' won't match a word boundary. I'll edit my answer. – Philippe Leybaert Jul 11 '12 at 19:25

score 1 · Answer 2 · answered Jul 11 '12 at 18:55

1

You might not even need a regex... try

string result = s.Replace("(old)", "<b>(old)</b>");

or

string result = s.Replace("(", "<b>(").Replace(")", ")</b>");

answered Jul 11 '12 at 18:55

Stephen Hewlett

I have a HTML content and I would like use the Regular Expression,your solution works for me.but the others does not work. – Houshang.Karami Jul 11 '12 at 19:05

2 Answers2