Regex issues using Pattern-matching in C#

Question

I'm working with regex's using the RegEx.replace method and I'm running into some strings my patterns are not working for.

For strings such as:

"Av.Av. Italy"
"Av.  Av. Italy"
"Av. . Av. Italy"

I'm trying to replace the Av's and remove all the extra periods and whitespaces so I tyr to use this regex

 rgx = new Regex(@"(Av\.).(Av\.)");
 address = rgx.Replace(address, replacement);

[edit] I want all of the above strings to end up just saying

"Av. Italy"

But it doesn't change anything.

I also wanted to use a regex to get random periods that appear on some strings (eg: "word . other word") with

rgx= new Regex(@"\b\.\b");

But that doesn't do anything either...

Am I using the escape sequences wrong?

Answer 1

You can perhaps use this regex:

rgx = new Regex(@".*(?:(Av\.)\s*)+");
address = rgx.Replace(address, replacement);

regex101 demo

ideone demo

The regex takes any characters, where there's an Av. somewhere ahead, eats all the duplicate Av. and spaces and replaces those with a single Av. (plus a space that got eaten by the regex).

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For the second one, maybe that?

rgx= new Regex(@" \.(?= )");

\b matches between two word characters, namely between \w and \W no matter in what order they come, and \w is [a-zA-Z0-9_] while \W is the opposite. Since both space and . are in \W, you wouldn't have a match. Then, I used a space instead of \s because \s matches newlines, which I don't think is what you're looking for :)

The lookahead is to prevent the removal of two white spaces. Otherwise Word . Word would become WordWord.

Answer 2

For the first this rgx = new Regex(@"(Av\.*[\s]*)*"); will work for you. For the second you must provide an example.