c# - Standalone numbers Regex?

Question

I currently use this regex:

(d+)

the problem that i can get 2 strings:

"2112343 and alot of 4.99"

OR

"4.99 and alot of 2112343 "

I get this from both:

[2112343, 4, 99]

I need to get only the 2112343... How can i achieve this?

Answer 1

Using lookaround, you can restrict your capturing to only digits which are not surrounded by other digits or decimal points:

(?<![0-9.])(d+)(?![0-9.])

Alternatively, if you want to only match stand-alone numbers (e.g. if you don't want to match the 123 in abc123def):

(?<!S)d+(?!S)