regex: Finding a pattern of alternating numbers and strings

Question

I'm trying to find the following pattern:

(NUMBERS)(STRING)(NUMBERS)(STRING)(NUMBERS)(STRING)

with at least one group of (NUMBERS)(STRING) present. I also want to get in the match the number and the string separately.

Example:

1234abc234qwy2342nioo
23oin234noik32342noi
234nio234koi2341nio

The output I want is as follows:

1. 1234, abc, 234, qwy, 2342, nioo
2. 23, oin, 234, noik, 32342, noi

However, if the input is just a number, I don't want it to match with the pattern.

I came up with the following regex:

^(\d*)([a-z]*)(\d*)([a-z]*)(\d*)([a-z]*)$

Regex Example

However, now it captures if I give it a number alone as well. For example, it matches the following patterns:

2342324

Is there a way I can impose on the regex that it captures at least one group of (NUMBERS)(STRINGS) and not match the numbers alone.

Answer 1

The problem is that you are using the *, which means zero-or-more. In other words, if you use *, it's essentially optional. + means one-or-more, so that's more appropriate in your case. For instance:

^(\d+[a-z]+){1,3}$

Or, if you want to retain the capture groups:

^(?:(\d+)([a-z]+)){1,3}$

Or:

^(\d+)([a-z]+)(?:(\d+)([a-z]+))?(?:(\d+)([a-z]+))?$