0
$\begingroup$

How many languages can a Regular Expression describe is it only one or infinite? I have tried to google it but i haven't found any answer?

I know that a Regular Expression describes a Regular Language?

$\endgroup$
1
  • $\begingroup$ One language, though there might be infinitely many strings described by a regular expression. $\endgroup$ May 12, 2021 at 17:05

3 Answers 3

2
$\begingroup$

If you look at the definition of regular expressions (they are usually defined in parallel to the language denoted) you see there is only one language denoted by a given expression. That language could be empty, finite or infinite, but that is another question.

$\endgroup$
3
$\begingroup$

Every regular expression describes one language --- the language of words matched by the regular expression, or, in other words, the language of words accepted by the finite automaton corresponding to the regular expression.

$\endgroup$
0
$\begingroup$

A language is described by a regular expression if and only if it is regular.

There are infinitely many regular languages over any fixed alphabet.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.