Return only one group with OR condition in Regex

问题

I have to write a Regex to fetch Email Address from a sentence. I want it to be returned with Group 1 only.

Regex:

\[mailto:(.+)\]|<(.+@.+\..+)>

Input String:

Hello my Email Address is <foo@hotmail.com> - Return foo@hotmail.com as Group1.
Hello my Email Address is [mailto: foo@hotmail.com] - Return foo@hotmail.com as Group2.

I want if any of the string matches then it should be returned in Group1.

Is there any way to do this?

回答1:

You may use regular expression:

(?=\S+@)([^<\s]+@.*(?=[>\]]))

• (?=\S+@) Positive lookahead, assert that what follows is any non-whitespace characters followed by @.
• ([^<\s]+@.*(?=[>\]])) Capture group. Capture any non-whitespace, non ^ character followed by @, and anything up to either a ] or > character.

You can test the regular expression here.

来源：https://stackoverflow.com/questions/51542531/return-only-one-group-with-or-condition-in-regex