Find bbtag pairs
A “bb-tag” looks like [tag]...[/tag], where tag is one of: b, url or quote.
For instance:
[b]text[/b] [url]http://google.com[/url]BB-tags can be nested. But a tag can’t be nested into itself, for instance:
Normal: [url] [b]http://google.com[/b] [/url] [quote] [b]text[/b] [/quote] Can't happen: [b][b]text[/b][/b]Tags can contain line breaks, that’s normal:
[quote] [b]text[/b] [/quote]Create a regexp to find all BB-tags with their contents.
For instance:
let regexp = /your regexp/flags; let str = "..[url]http://google.com[/url].."; alert( str.match(regexp) ); // [url]http://google.com[/url]If tags are nested, then we need the outer tag (if we want we can continue the search in its content):
let regexp = /your regexp/flags; let str = "..[url][b]http://google.com[/b][/url].."; alert( str.match(regexp) ); // [url][b]http://google.com[/b][/url]Opening tag is \[(b|url|quote)].
Then to find everything till the closing tag – let’s use the pattern .*? with flag s to match any character including the newline and then add a backreference to the closing tag.
The full pattern: \[(b|url|quote)\].*?\[/\1].
In action:
let regexp = /\[(b|url|quote)].*?\[\/\1]/gs; let str = ` [b]hello![/b] [quote] [url]http://google.com[/url] [/quote] `; alert( str.match(regexp) ); // [b]hello![/b],[quote][url]http://google.com[/url][/quote]Please note that besides escaping [, we had to escape a slash for the closing tag [\/\1], because normally the slash closes the pattern.