<%$, <%@, <%=, <%# ... what's the deal?

I've programmed in both classic ASP and ASP.NET, and I see different tags inside of the markup for server side code.

I've recently come across a [good blog on MSDN][1] that goes over the difference between:

- `<%=` (percentage together with equals sign) and
- `<%#` (percent sign and hash/pound/octothorpe)

(`<%#` is evaluated only at databind, and `<%=` is evaluated at render), but I also see:

- `<%$` (percent and dollar sign) and
- `<%@` (percent sign and at symbol).

I believe `<%@` loads things like assemblies and perhaps `<%$` loads things from config files? I'm not too sure.

I was just wondering if anyone could clarify all of this for me and possibly explain why it's important to create so many different tags that seemingly have a similar purpose?


[1]:

[To see links please register here]

You've covered 2 of them (<%# is evaluated only at databind, and <%= is evaluated at render), and the answer for "`<%@`" is that it's compiler directives (ie., stuff like what you'd put on a compiler's command line).

I don't know about "`<%$`".

- `<% %>` - is for [inline code](

[To see links please register here]

) (especially logic flow)
- `<%$ %>` - is for [evaluating expressions](

[To see links please register here]

) (like resource variables)
- `<%@ %>` - is for [Page directives](

[To see links please register here]

), registering assemblies, importing namespaces, etc.
- `<%= %>` - is short-hand for `Response.Write` (discussed [here](

[To see links please register here]

))
- `<%# %>` - is used for [data binding expressions](

[To see links please register here]

).
- `<%: %>` - is short-hand for [Response.Write(Server.HTMLEncode())][1] ASP.net 4.0+
- `<%#: %>` - is used for [data binding expressions](

[To see links please register here]

) and is automatically HTMLEncoded.
- `<%-- --%>` - is for [server-side comments](

[To see links please register here]

)


[1]:

[To see links please register here]