"Reverse" order regex - closest "above" match

Question

this is example of some string.

<div>other text</div> some text abc , <div>need_match_this</div> bbbb <p>hsa</p> aa <span>hello</span>

I know only end of string "<span>hello</span>" and I need to match text in closest "above" div.

I used this regex:

\<div\>(.*?)\<\/div\>.*?\<span\>hello\<\/span\>

But this is not working for me because I need to return text of closest div only, not first div in string.

Is there any regex solution to resolve this?

Please help.

Thank you

Answer 1

You need to use a negative lookahead based regex instead of in-between .*?, since .*? would also match opening or closing div tags.

<div>((?:(?!<\/?div>).)*?)<\/div>(?:(?!<\/?div>).)*?<span>hello<\/span>

DEMO

(?:(?!<\/?div>).)*? forces the regex engine to match any character but not of <div> or </div>. That is, before matching each character, this regex would check for that particular character is not the starting character in <div> or </div> . If yes, then it would match that particular character. If no, match will fail abruptly and the following character won't be matched.

Example:

string - <div></div>

regex - <div>((?:(?!<\/?div>).)*?)<\/div>

For this input, the above mentioned regex would capture the in-between empty string (ie, the empty string exists between the opening and closing div tags). (?!<\/?div>). in the above would check for the following char must not be a starting char in <div> or </div> but this fails since the following char is < which is a staring char in </div>. Because we defined this particular regex to repeat zero or more times, (?:(?!<\/?div>).)*?, it captures the in-between empty string.