RegEx to exclude a specific string constant

Question

Can regular expression be utilized to match any string except a specific string constant let us say  ABC    Is this possible to exclude just one specific string constant  Thanks your help in advance

User · Answer

Try this regular expression       0 2     A    A  B   AB  C     4       It describes three cases    less than three arbitrary character exactly three characters  while either   the first is not A  or the first is A but the second is not B  or the first is A  the second B but the third is not C  more than three arbitrary characters

User · Answer

This isn t easy  unless your regexp engine has special support for it  The easiest way would be to use a negative-match option  for example    var      foo       or die  too much foo     If not  you have to do something evil    var              f      f  o      fo  o      foo           or die  too much foo     That one basically says  if it starts with non-f  the rest can be anything  if it starts with f  non-o  the rest can be anything  otherwise  if it starts fo  the next character had better not be another o

User · Answer

You have to use a negative lookahead assertion       ABC     You could for example use the following       ABC           If this does not work in your editor  try this  It is tested to work in ruby and javascript        ABC

User · Answer

In  NET you can use grouping to your advantage like this   http   regexhero net tester  id 65b32601-2326-4ece-912b-6dcefd883f31  You ll notice that    ABC        Will grab everything except ABC in the 2nd group   Parenthesis surround each group   So  ABC  is group 1 and     is group 2   So you just grab the 2nd group like this in a replace    2   Or in  NET look at the Groups collection inside the Regex class for a little more control   You should be able to do something similar in most other regex implementations as well   UPDATE  I found a much faster way to do this here  http   regexhero net tester  id 997ce4a2-878c-41f2-9d28-34e0c5080e03  It still uses grouping  I can t find a way that doesn t use grouping    But this method is over 10X faster than the first

User · Answer

You could use negative lookahead  or something like this       A  A   B  B   C                Maybe it could be simplified a bit

[regex] RegEx to exclude a specific string constant

Examples related to regex

Examples related to regex-negation