正则表达式获取字符串的第一部分

Question

I have this regex

(?<=\d\.\s).+(?=\s-\s)

It works great when I have a string like

3. product - sub product

The regex gives me the product (first part). If a sub-product exists it is delimited from the product by a dash surrounded with spaces ( - ).

However, there are some products which do not have sub-product. For example:

6. ComprehensiveBolt

The regex should give me comprehensiveBolt but it does not return anything.

What update do I need to make to my regex so I can get the product regardless of the presence, or otherwise, of a sub-product?

Answer 1

This is one way.
Note this is only needed if your product could be a phrase.

(?<=\\d\\.\\s)(?:(?!\\s-\\s|\\d\\.\\s).)+

https://regex101.com/r/uC2yDs/1

Partial explanation

 (?<= \d \. \s )               # This must be behind
 (?:                           # -----------
      (?!                           # Neg assertion
           \s - \s                       # Not this ahead
        |  \d \. \s                      # Nor this ahead
      )
      .                             # Ok, grab this character
 )+                            #  1 to many times