Regex for matching alternating sequences

Question

I'm working in Java and having trouble matching a repeated sequence. I'd like to match something like:

a.b.c.d.e.f.g.

and be able to extract the text between the delimiters (e.g. return abcdefg) where the delimiter can be multiple non-word characters and the text can be multiple word characters. Here is my regex so far:

([\\w]+([\\W]+)(?:[\\w]+\2)*)

(Doesn't work)

I had intended to get the delimiter in group 2 with this regex and then use a replaceAll on group 1 to exchange the delimiter for the empty string giving me the text only. I get the delimiter, but cannot get all the text.

Thanks for any help!

Answer 1

Why not use String.split?

Answer 2

Replace (\w+)(\W+|$) with $1. Make sure that global flag is turned on.

It replaces a sequence of word chars followed by a sequence of non-word-chars or end-of-line with the sequence of words.

String line = "Am.$#%^ar.$#%^gho.$#%^sh";
line = line.replaceAll("(\\w+)(\\W+|$)", "$1");
System.out.println(line);//prints my name

Answer 3

Why not ..

• find all occurences of (\w+) and then concatenate them; or
• find all non word characters (\W+) and then use Matcher.html#replaceAll with an empty string?

Answer 4

Replace (\w+)\W+ by $1