Question

Good evening, I’m learning regular expressions to PHP. I am not managing to make 1 to 30 and 1 to 10. For 1 to 9, I thought [1-2-3-4-5-6-7-8-9] or [1-9]{1}, which is more correct? Thanks in advance 🙂

Answer 1

For 1 to 9, there is straight forward regex that is [1-9].
For 1 to 10, and 1 to 30, a combination of rules are to be applied.
For 1 to 10, you can use this:

10|[1-9]

For 1 to 30, this regex could be used:

(30)|([12][0-9])|([1-9])

or

(30)|([12]\d)|([1-9])

the first part 30, would look for exact match i.e. 30.
the second part [12]\d or [12][0-9], would look for numbers between 10 to 29.
the last part [1-9] would look for numbers between 1-9.