Regex expression in Dart

Question

I want to catch all of the cases that are exactly called number and then all of the cases where number is surrounded by underscores, for example hey_number, number_hey or hey_number_hey, the thing is that I don't want to catch cases like hey_numbers or hey_numberrr

I did end up with

(^number$)|(.*[_]{1}number.*)|(.*number[_]{1}.*)

but it still catches hey_numbers

Answer 1

Applying this expression

(?:\w+_|\b)number(?:_\w+|\b)

on this text:

hey_number, number_hey or hey_number_hey, the thing is that I don't want to catch cases like hey_numbers or hey_numberrr or nnumber or nnumber_chesu

you get:

hey_number
number_hey
hey_number_hey

You can try it with this tester.