Regex - extract string between double quotes where line starts with a keyword

Given the following lines:

classes!("text-xl", "text-blue-500")
String::from("test")
classes!("text-sm")

I wish to extract text-xl, text-blue-500 and text-sm and potentially any other strings within classes!

What I have so far is:

• (?<=classes!).* - this gives me everything after classes! but not the exact values
• (?!^")".*?" - this gives me the values I want with but with the quotes
• I use the global and multi line flags

Solution 1:

If you are using Javascript, and the positive lookbehind is supported (you don't need the multiline flag, only the global flag)

(?<=classes!\((?:"[^"]*",\s*)*")[^"]*(?=")

• (?<= Positive lookbehind to assert to the left
  • classes!\( Match classes!(
  • (?:"[^"]*",\s*)* Match optional repetitions of "...",
  • " Match a double quote
• ) Close lookbehind
• [^"]* Match optional chars other than "
• (?=") Assert " to the right

Regex demo

const regex = /(?<=classes!\((?:"[^"]*",\s*)*")[^"]*(?=")/g;
const str = `classes!("text-xl", "text-blue-500")
String::from("test")
classes!("text-sm")
`;
console.log(str.match(regex))

Solution 2:

You could try a non fixed-width lookbehind like so:

(?<=^classes!\("(?:[^"]*"[^"()]*")*)[^"]*

See an online demo

• (?<= - Open a positive lookbehind;
  • ^classes!\(" - Start-line anchor and match literally 'classes!("';
  • (?:[^"]*"[^()"]*")* - A nested non-capture group to match (0+ times) any char other than quotes (and paranthesis), a quote and that same sequence repeated.
  • ) - Close lookbehind;
• [^"]* - Match 0+ (Greedy) characters other than quotes.