Regex match all words enclosed by parentheses and separated by a pipe

Question

I think an image a better than words sometimes.

My problem as you can see, is that It only matches two words by two. How can I match all of the words ?

My current regex (PCRE) : ([^\\|\\(\\)\\|]+)\\|([^\\|\\(\\)\\|]+)

The goal : retrieve all the words in a separate groupe for each of them

Answer 1

You can use an infinite length lookbehind in C# (with a lookahead):

(?<=\([^()]*)\w+(?=[^()]*\))

See the regex demo . Details :

• (?<=\\([^()]*) - a positive lookbehind that matches a location that is immediately preceded with ( and then zero or more chars other than ( and )
• \\w+ - one or more word chars
• (?=[^()]*\\)) - a positive lookahead that matches a location that is immediately followed with zero or more chars other than ( and ) and then a ) char.

Another way to capture these words is by using

(?:\G(?!^)\||\()(\w+)(?=[^()]*\))

See this regex demo . The words you need are now in Group 1. Details :

• (?:\\G(?!^)\\||\\() - a position after the previous match ( \\G(?!^) ) and a | char ( \\| ), or ( | ) a ( char ( \\( )
• (\\w+) - Group 1: one or more word chars
• (?=[^()]*\\)) - a positive lookahead that makes sure there is a ) char after any zero or more chars other than ( and ) to the right of the current position.

Extracting the matches in C# can be done with

var matches = Regex.Matches(text, @"(?<=\([^()]*)\w+(?=[^()]*\))")
    .Cast<Match>()
    .Select(x => x.Value);

// Or
var matches = Regex.Matches(text, @"(?:\G(?!^)\||\()(\w+)(?=[^()]*\))")
    .Cast<Match>()
    .Select(x => x.Groups[1].Value);

Answer 2

In c# you can also make use of the group captures using a capture group.

The matches are in named group word

\((?<word>\w+)(?:\|(?<word>\w+))*\)

• \\( Match (
• (?<word>\\w+) Match 1+ word chars in group word
• (?: Non capture group
  • \\| Match |
  • (?<word>\\w+) Match 1+ word chars
• )* Close the non capture group and optionally repeat to get all occurrences
• \\) Match the closing parenthesis

Regex demo