[LON-CAPA-users] Regular expressions in string response

Gerd Kortemeyer lon-capa-users@mail.lon-capa.org
Tue, 1 May 2007 09:14:03 -0400


On May 1, 2007, at 8:33 AM, Robert_Brewington@er.monroe.edu wrote:

> I am trying to set up a string response question that takes the  
> student
> answer and removes blanks before comparing to the correct answer.  
> Hopefully
> someone has a code snippet that does this?
> Student input:
> a b  c
> I want to match to
> /^(abc|acb|bca)\b)

\s* matches any number of spaces, including zero:

/^(a\s*b\s*c|a\s*c\s* ...) ...

> (Incidentally, what does the "b" do in this expression?)

Matches a word boundary, and is not appropriate if you want to  
consider spaces. Your whole expression would be


> I am looking for something like the vi command to remove spaces:
> s/ //g

Rather than removing them, I would match them.



As the saying goes:

     You have a problem, and think: "Oh, I'll just use a regular  
expression!" - now you have two problems.

But seriously, I love regular expressions.

- Gerd.