In some regex implementations there are only nine of them, however, with most contemporary Javascript implementations you can have up to 99 such capture-groups (where such groups are 1-based).

Regular expressions are great, but remember, the objective is parsing, that means extracting information from a string. Capture groups are usually how you deal with variability.

Working with regular expressions I’m also going to cover how to work with regular expressions in JavaScript, though the concepts learned here apply to other languages as well.