I am trying to write a regular expression which finds all the comments in text.
For example all between /* */
.
Example:
/* Hello */
The right answer - it is impossible. You cannot write a regular expression that would be able to correctly find all comments, or even one type of comments - single-line or multiline.
Regular expressions can only provide a partial match, one that would would cover perhaps 90% of all cases, but that's it.
The syntax for regular expression is so complex, it is only possible to identify them correctly in 100% of cases by doing a full expression evaluation, which in turn is based on tokenizing the code. The latter is a huge task, which is implemented by all AST parsers today. See AST Explorer
Only a proper-written AST parser can tell you precisely where all regular expressions are located in your code. You would have to write a parser then based on that.
Or, you could use one of the existing libraries that already do all that, like decomment.
RegEx examples where any head-on approach is going to stumble, being unable to tell a regular expression from a comment block:
/\//
- it will think this reg-ex is a single-line comment/\/*/
- it will think this reg-ex opens a multi-line comment