How is the AND/OR operator represented as in Regular Expressions?

I'm currently programming a vocabulary algorithm that checks if a user has typed in the word correctly. I have the following situation: The correct solution for the word would be "part1, part2". The user should be able to enter either "part1" (answer 1), "part2" (answer 2) or "part1, part2" (answer 3). I now try to match the string given by the user with the following, automatically created, regex expression:

^(part1|part2)$ 

This only returns answer 1 and 2 as correct while answer 3 would be wrong. I'm now wondering whether there's an operator similar to | that says and/or instead of either...or.

May anyone help me solve this problem?

6 Answers

I'm going to assume you want to build a the regex dynamically to contain other words than part1 and part2, and that you want order not to matter. If so you can use something like this:

((^|, )(part1|part2|part3))+$ 

Positive matches:

part1 part2, part1 part1, part2, part3 

Negative matches:

part1, //with and without trailing spaces. part3, part2, otherpart1 

'^(part1|part2|part1,part2)$' 

does it work?

Not an expert in regex, but you can do ^((part1|part2)|(part1, part2))$. In words: "part 1 or part2 or both"

Does this work without alternation?

^((part)1(, \22)?)?(part2)?$ 

or why not this?

^((part)1(, (\22))?)?(\4)?$ 

The first works for all conditions the second for all but part2(using GNU sed 4.1.5)

Or you can use this:

^(?:part[12]|(part)1,\12)$ 

use
if in vim:

:s/{\|}/"/g 

will replace { and } on " so {lol} becomes "lol"