For example:
/* comment1
comment2
comment3 */

I want delete the comments (including /*and*/)
One way is using macro. How to do this using just replace command?
How to represent it in regular expression ?
I tried ^(/*^)^(*^)^(*/^) or ^(\/\*^)^(*^)^(\*\/^) or ^(^/^*^)^(*^)^(^*^/^), all cannot work.
I also tried in VIM: %s/\(\/\*\)\(*\)\(\*\/\)//, also doesn't work, I know * limits us to only one line search,
so any solution to describe the contents that have several lines?

Thanks a lot

As a Perl regex, when nested comments are not allowed (/* This /* comment is */ nested */):

(?s)/\*.*?\*/

If you want to allow one level of nesting:

(?s)/\*(?:(?!\*/|/\*).)*+(?:/\*(?:(?!\*/|/\*).)*+\*/(?:(?!\*/|/\*).)*+)*+.*?\*/

If you want to allow two levels of nesting, you'd better give up.

And no, I didn't come up with the second regex here, it's from RegexBuddy's library.

Note that UltraEdit does *not* support RegEx fully. UltraEdit cripples RegEx by applying it on a line by line basis, whereas RegEx is supposed to apply to the entire document for true multi-line support.

I love UltraEdit, but when I need more advanced RegEx support, I use JGSoft's EditPad Pro. I wish UltraEdit would support RegEx fully, but despite numerous complaints and requests, it has still never happened. So, until they do, I'm stuck using two text editors.

That is true; I could have written the same thing, word for word. The regex should still work in UE, though

Great, thanks to both of you

This perl style regular expression will match a comment block from the first "/" in "/*" to the last "/" in "*/": I am using UEStudio v10 and it finds/highlights comment blocks when this perl regex is used, it even handles the case where there are multiple '*' after the first "/" and/or multiple '*' before the last "/".

hth