For Each m As Match In Regex.Matches(html, pattern, RegexOptions.IgnoreCase) contents = m.Groups("table").Value 'contents will equal: '1:Some table code '2:Some other table code. A cool feature of the .NET RegEx-engine is the ability to match nested constructions, for example nested parenthesis. into the optional part: The .*? My knowledge of the regex class is somewhat weak. That right there matches a full group of nested parentheses from start to end. This is the second article in a short series where I go in depth with the .NET RegEx engine and Regex class. Les brackets (…) définissent le groupe de capture 1 et ce groupe est associé à plusieurs reprises à +. Let’s apply the regex (?'open'o)+(? (? groups are in the order in which they are defined (in order by open parenthesis). When there are nested multi line comments then the regex does not work as expected. This becomes important when capturing groups are nested. The tag attributes: class="my". Trying the other alternative, one is matched by the second capturing group, and subsequently by the first group. But actually in this case you could also just move the .*? The first group is then repeated. With the negative lookahead (?:(?!src). the contents of the first parentheses group, etc. This expression requires capturing two parts of the data, both the year and the whole date. Inside a character class, different rules apply. In addition, local users and computers can also be members of this group. Javascript - Using Concatenated String in Regex I'm trying to find if a given string of digits contains a sequence of three identical digits. Two substrings per match are necessarily captured and saved; these are useless to you. into the optional src part. have in a list. YES: YES: YES: YES: YES: YES: YES: YES: YES: YES: YES: YES: YES In this case the numbering also goes from left to right. Next. Shouldn't $2 match the content of the src attribute of a script tag? I'm thinking that regular expressions by themselves can't do exactly what I'm looking for, so here's my modification to work around the problem: Before, I wanted to avoid setting non-standard attributes on the replacement span. I will describe this feature somewhat in depth in this article. How to set 2 buttons trigger from same event? For the following strings, write an expression that matches and captures both the full date, as Groups info. if you remove the ? I'm stumped that with a regular expression like: "((blah)*(xxx))+" That I can't seem to get at the second occurrence of ((blah)*(xxx)) should it exist, or the second embedded xxx. They capture the text matched by the regex inside them into a numbered group that can be reused with a numbered backreference. This time, \1 matches one as captured by the last iteration … If you are an experienced RegEx developer, please feel free to go forward to the part "The Push-down Automata." javascript regex replace regex-group Referencing nested groups in JavaScript using string replace using regex Because of the way that jQuery deals with script tags, I've found it necessary to do some HTML manipulation using regular expressions (yes, I know... not the ideal tool for the job). In Part IIthe balancing group is explained in depth and it is applied to a couple of concrete examples. Boost defines a member of smatch called nested_results() which isn't part of the VS 2010 version of smatch. The capture that is numbered zero is the text matched by the entire regular expression pattern.You can access captured groups in four ways: 1. If you don't need the matched substring to be recalled, prefer non-capturing parentheses (see below). The nested groups are read from left to right in the pattern, with the first capture group being after your first group it works. Learn how to test regular expressions and use them in appropriate string and regex methods in Javascript. Just for completeness: /