Javascript Regular Expression lessons out of order

I’m not sure if this is the correct place to raise this but:

The solution given to this lesson: https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/regular-expressions/restrict-possible-usernames
uses the pattern syntax [0-9]{2,0}.

However, that syntax is not taught until 3 lessons later, here:
https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/regular-expressions/specify-upper-and-lower-number-of-matches

A different solution (say: /^[a-z][a-z]$|^[a-z][a-z]+[0-9]*$|^[a-z][0-9][0-9]+$/) would work without using the as-of-yet untaught syntax).
Suggest either reordering the lessons, or changing the hinted solution.

1 Like

@teachermanalex Thanks for letting us know. We don’t have a problem with solutions which might involve concepts/syntax the user might not have encountered yet, but I agree that at least one of the solutions should not involve syntax not yet covered in the curriculum.

I have added another solution to the hint/solution page, which is a bit simpler than your suggestion.

1 Like