I have this string:
"Common Waxbill - Estrilda astrild"
How can I write 2 separate regexes for the words before and after the hyphen? The output I would want is:
"Common Waxbill"
and
"Estrilda astrild"
If you cannot use look-behinds, but your string is always in the same format and cannout contain more than the single hyphen, you could use
^[^-]*[^ -] for the first one and \w[^-]*$ for the second one (or [^ -][^-]*$ if the first non-space after the hyphen is not necessarily a word-character.
A little bit of explanation:
^[^-]*[^ -] matches the start of the string (anchor ^), followed by any amount of characters, that are not a hyphen and finally a character thats not hyphen or space (just to exclude the last space from the match).
[^ -][^-]*$ takes the same approach, but the other way around, first matching a character thats neither space nor hyphen, followed by any amount of characters, that are no hyphen and finally the end of the string (anchor $). \w[^-]*$ is basically the same, it uses a stricter \w instead of the [^ -]. This is again used to exclude the whitespace after the hyphen from the match.
This is quite simple:
.*(?= - ) # matches everything before " - "
(?<= - ).* # matches everything after " - "
See this tutorial on lookaround assertions.
Another solution is to string split on the hyphen and remove white space.
来源：https://stackoverflow.com/questions/37190978/regex-get-text-before-and-after-a-hyphen