Regex match commas and periods unless surrounded by digits

Question

I have the regular expression:

[^\w-,.]|((?<!\d)[,.]

which matches all non [\w-,.] or, using a negative lookbehind, any comma or period not preceded by a digit.

Using java-compatible regex, I need to capture:

• [^\w,.]
• , unless preceded and followed by a \d
  • (eg no capture for 1,2,3 but capture [\s,] in 1, 2, 3)
• . unless preceded and followed by a \d
  • (eg no capture for 12.32 but capture for 23.)

My regex gets me close, however, I am not able to capture the commas and periods in the following examples:

• 1.a (need to capture the period)
• 32, foo (need to capture comma and whitespace)
• 1.1. (need to capture the last period)

The following example illustrates example of working and non-working strings to match.

https://regex101.com/r/pWcwXa/2

Answer 1

How about this ?

[^\w-,.]|((?<!\d)[,.]|[,.](?!\d))

Demo,,, in which I slightly changed your regex only to add the case which not followed by a digit