CODEWITHSUNDEEP
regexstringstring-parsing
dreyln
dreyln

Reputation: 880

Regular Expression Troubles

Given the following type of string:

"#First Thing# #Another One##No Space# Main String #After Main# #EndString#"

I would like to come up with a regular expression that can return all the text surrounded by the # symbols as matches. One of the things giving me grief is the fact that the # symbol is both the opening and closing delimiter. All of my attempts at a regex have just returned the entire string. The other issue is that it is possible for part of the string to not be surrounded by # symbols, as shown by the substring "Main String" above. Does anyone have any ideas? I have toyed around with Negative Look-behind assertion a bit, but haven't been able to get it to work. There may or may not be a space in between the groups of #'s but I want to ignore them (not match against them) if there are. The other option would be to just write a string parser routine, which would be fairly easy, but I would prefer to use a regex if possible.

Upvotes: 1

Views: 78

Answers (3)

Seth Robertson
Seth Robertson

Reputation: 31461

/((#[^#]+#)|([^#]+))/

Perhaps something like the above will match what you want.

This will match the space in between two hashes. Hmm.

/((#[^#]+#)|([^#]*[^#\s]+[^#]*))/

That will get rid of the nasty space, I think.

Upvotes: 2

NullRef
NullRef

Reputation: 3743

Try this. The first and last groups should not be captured and the .*? should be lazy

(?:#)(.*?)(?:#)

I think this is what you really need:

((#[^#]+#)|([^#]*[^#\s]+[^#]*))

but it will not capture the #'s around Main String

Upvotes: 1

Alex Aza
Alex Aza

Reputation: 78487

[Edit]

I think that this is what you need:

(?<=#)[^#]+?(?=#)

With input #First Thing# #Another One##No Space# Main String #After Main# matches:

  • First Thing
  • Another One
  • No Space
  • Main String
  • After Main

The second match is the space between Thing# and #Another.

[EDIT] To ignore space:

(?<=)(?!\s+)[^#]+?(?=#)

If you want to ignore trailing spaces:

(?<=)(?!\s+)[^#]+?(?=\s*#)

Upvotes: 1

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