regex to extract by be removing a pattern if present at the end

Question

I am trying to extract value from field if containing "- E1/E2" and ignore the rest.

I have used (?<value>.*)\s+-\s+E[1-3]* but it doesn't extract if doesn't contain E1/E2.

below sample values. it doesn't work for 2,4 sample data. Unable to understand how do i make E1/E2 as optional.

1. hello - I am here at - E1
2. Kilo
3. How are you - E3
4. Cool
5. simple - E1 - Dev
6. another simple - E2 QA

Answer 1

You can use

^(?<value>.*?)(?:\s+(?:-\s+)?E[1-3].*)?$

See the regex demo.

Details

• ^ - start of string
• (?<value>.*?) - Group "value": zero or more chars other than line break chars as few as possible
• (?:\s+(?:-\s+)?E[1-3].*)? - an optional non-capturing group:
  • \s+ - one or more whitespaces
  • (?:-\s+)? - an optional sequence of - and one or more whitespaces
  • E[1-3] - E and a digit from 1 to 3
  • .* - zero or more chars other than line break chars as many as possible
• $ - end of string.