Regex to match at least n times but not more than m times

Question

I want a regular expression that could match the string %*--- with at least 1 hyphen but the expression should not be matched if there are more than 3 hyphens. So far I have come up with /^%?\*{1}\s*(\- *){1,3}/ but it is still matching when the hyphens exceed 3.

I have also tried ? after the range {1,3} but its not meeting the requirement.

Answer 1

Although it's often written as {min,max} in tutorials and references, the enumerated quantifier does not mean not more than max. If it sees three hyphens, -{1,3} will consume all three, but it doesn't care what the next character is (if there is one). It's just like all other quantifiers in this regard: it consumes as much as it can, then it hands control to the next part of the regex.

That's why the other responders suggested using an end anchor ($). If you can't use an anchor, or don't want to, you can use a negative lookahead instead:

/^%\*-{1,3}(?!-)/

Answer 2

You need a $ at the end, and your regex can be greatly simplified:

/^%\*--?-?$/

See demo.