How can a closing bracket be dealt with inside a regex match?

I’m trying to match a set of text inside a bracketed item as a match group.

That text may or may not itself have a bracket in it. To complicate matters, the text may or may not have quotes around it or exist at all, here are some examples of expected output:

[quote=John]abc[/quote] // John
[quote="John"]abc[/quote] // "John"
[quote='John']abc[/quote] // 'John'
[quote='Joh]n']abc[/quote] // 'Joh]n'
[quote='Joh[]n']abc[/quote] // 'Joh[]n'
[quote]abc[/quote] // match

The pattern I’ve come up with so far is \[quote[=]?["]?([\s\S]*?)["]?\]|\[\/quote\] but it is failing with the 4-5 examples above because it is seeing the first closing bracket

This would be used in dart

>Solution :

You may use this regex:

\[quote(?:=(.+?))?][^\]\[]*\[/quote]

RegEx Demo

RegEx Breakdown:

• \[quote: Match [quote
• (?:: Start non-capture group
  • =: Match a =
  • (.+?): Match 1+ of any character and capture in group #1
• )?: End non-capture group. ? makes this optional match
• ]: Match closing ]
• [^\]\[]*: Match 0 or more of any character that is not [ and ]
• \[/quote]: Match [/quote]