How to check from a regular expression if there is a certain value between two strings, for example, the tags <code> and </code> ?
I want, for example, to know if there is a value between "03" between the two tags. How to write an expression that meets this need?
HTML is not a regular language and therefore can not be rendered by a regular expression.
You should use an appropriate tool for these cases.
If you have a "regular" interval in which you are sure to always follow the same pattern, you can use REGEX.
String s = "<div style=\"border:1px solid #CCC\">03</div>";
String t = "div";
String p = "<("+t+").*>([^<]*?)</\1>";
Pattern r = Pattern.compile(p, Pattern.CASE_INSENSITIVE);
Matcher m = r.matcher(s);
m.find();
System.out.print(m.group(2));