Regex to match a whole string in C#?

Question

I have the following list of produtcs (in a .txt file) :

#ART#NC3FX;price1
#ART#NC3FX;price2
#ART#NC3FX;price3
#ART#NC3FXX;price1
#ART#NC3FXX;price2
#ART#NC3FXX;price3
#ART#NC3FXX;price1
#ART#NC3FXX;price2
#ART#NC3FXX;price3
#ART#NC3FX-HD;price1
#ART#NC3FX-HD;price2
#ART#NC3FX-HD;price3

I'd like to get all the occurrences of the first one ( ART#NC3FX ).

Using this regular expression

@"(^|\b)#ART#NC3FX(\b|$)";

I retrieve the first three lines, which is fine, but I also get the lines for the reference #ART#NC3FX-HD .

What should I do to prevent this from happening ?

Thanks !

Answer 1

Your regex finds a match because the - hyphen is not a word character, and you tell the regex engine (with \\b ) that the character after D should be a non-word character. So, you get a match.

You may use a negative lookahead:

@"\B#ART#NC3FX(?![\w-])"

See regex demo

The \\B will match a position at the beginning of the string or a non-word boundary, and (?![\\w-]) lookahead will fail a match if the string is followed with a word character or a hyphen. If you test independent strings replace \\B with ^ (start of string).

Answer 2

Im not sure if i understand your answer correctly, but why dont you look for the first ; like:

@"^#ART#NC3FX(;|$)"

EDIT: See Avinash's Answer