If the string you happen to match contains a lot of metacharacters, you end up with backslashes all over the place, which makes the result hard to read. Nested

If the string you happen to match contains a lot of metacharacters, you end up with backslashes all over the place, which makes the result hard to read. Nested groups and captures are also often hard to parse. FWIW, you forgot to double escape `\\\\.`, and didn't close the CSS comment (last alternative). "[(),]" // match the foo part... + "|\"(?:\\\\.|[^\"\\n])*\"" //... or, match the bar part in *double* quotes + "|'(?:\\\\.|[^'\\n])*'" //... or, match the bar part in *single* quotes + "|\/\*[\s\S]*?\*\/" // or match the comment Also, you're probably not familiar with the quirks of JS regexps, but the two string alternatives use non-capturing groups, and `[\s\S]` is the true "any" matcher, `.` doesn't match new lines. At last, `*?` is a non-greedy `*`. (Edited thrice, damn you italics).