Given the following two strings
?room=any_characters123&name=John
?room=any_characters123
I want to extract "any_characters123" using regular expression.
I've tried
(?<=room=)(\w)+(?=\&)
but this one fails on the second string (because the matched string must end with "&").
How can I edit my regular expression so that it matches any_characters123 in both strings?
Since javascript won't support lookbehinds, you need to use capturing group.
\?room=(\w+)
Example:
> var s = "?room=any_characters123&name=John"
> var s1 = "?room=any_characters123"
undefined
> var re = /\?room=(\w+)/;
undefined
> console.log(re.exec(s)[1])
any_characters123
undefined
> console.log(re.exec(s1)[1])
any_characters123
Try putting * in the end of your expression:
room=(\w+)\&*?
It will test for zero or plus ocurrences of &
This should do the trick:
/room=(\w+)&?/
/*
find "room=" then match any word characters (at least one) until you
possibly hit "&"
*/
Example:
/room=(\w+)&?/.test("?room=any_characters123")
// => true
"?room=any_characters123".match(/room=(\w+)&?/)
// => ["room=any_characters123", "any_characters123"]
Run the string through two regex tests, the one you already have, and then this one:
(?<=room=)(\w){1,}$
