Lookaheads do not consume any characters. It just checks if the lookahead can be matched or not: a(?!b)c So here after matching a it just checks if it is followed not by b but does not consume that not character (which is c) and is followed by c. How a(?!b)c matches ac ac | a … Read more
The Big Picture We will first look at this regex from the overall big picture algorithm, and then take a closer look at the specific implementation details later. The regex is an almost direct translation of the following Java code: static boolean isPalindrome(String s) { if (s.isEmpty()) { return true; } String g2 = null; … Read more
The answer is: Python re does not support identically named groups. Python PyPi regex module supports identically named named capturing groups: The same name can be used by more than one group, with later captures ‘overwriting’ earlier captures. All of the captures of the group will be available from the captures method of the match … Read more
The “Comparison to Perl 5” section of java.util.regex.Pattern lists many differences. For example, Java does not support conditional regex. For that, you need to use some external library like JRegex.
The problem is pretty simple really. This will do it: /^(?!.*foo\.htm$).*\.htm$/i.test(“/foo.htm”); // returns false
sed -i ‘/^foo/! s/^/bar/’ file.txt -i change the file in place /^foo/! only perform the next action on lines not ! starting with foo ^foo s/^/bar/ change the start of the line to bar
But I need the match result to be … not in a match group… For what you are trying to do, this should work. \K resets the starting point of the match. \bObject Name:\s+\K\S+ You can do the same for getting your Security ID matches. \bSecurity ID:\s+\K\S+
You can use infinite-width lookahead and lookbehind without any constraint now beginning with Visual Studio Code v.1.31.0 release. See proof: and another one (with (?<=@fmt\([^()]*)\w+ pattern, note the * in the lookbehind): See the Github [VSCode 1.31] ES2018 RegExp lookbehind assertions are now supported #68004 issue: As a result of moving to Electron 3.0, RegExp … Read more
The explicit way of saying “search until X but not including X” is: (?:(?!X).)* where X can be any regular expression. In your case, though, this might be overkill – here the easiest way would be [^z]* This will match anything except z and therefore stop right before the next z. So .*?quick[^z]* will match … Read more
July 1, 2020 Update Starting with the FireFox 78 version, RegExp finally supports lookbehinds, dotAll s flag, Unicode escape sequences and named captures, see the Release Notes: New RegExp engine in SpiderMonkey, adding support for the dotAll flag, Unicode escape sequences, lookbehind references, and named captures. Thank you very much, FireFox developers!!! 👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍👍 Lookbehinds are … Read more