What is the difference between <% %> and <%= %> in ASP.NET MVC

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Possible Duplicates:
What is the difference between <% %> and <%=%>?
C# MVC: What is the difference between <%# and <%=

I'm so confused with this.

Please explain the difference between this if possible..

What is the significance of that "=" there?

Edit:Thanks for all your answers.Please understand that It was hard to get any results by searching for "<%=" on google and on the search bar in stackoverflow as well.

This is a dupe for sure but I'm still struggling to find it. — mmx, Sep 08 '09 at 12:48
Will: searching for punctuation chars is hard. discussed on meta. — mmx, Sep 08 '09 at 12:50
Kobi: hopefully, in ASP.NET MVC, we don't see that one most of the time! Also, there's ``. — mmx, Sep 08 '09 at 12:55
I know its hard searching for this, thats why I didn't even bother looking for dupes. — , Sep 08 '09 at 13:16
See my post below. Searching for "asp.net bee stings" finds a couple of matches: http://stackoverflow.com/search?q=asp.net+bee+stings — Ahmad Mageed, Sep 08 '09 at 15:02
Because no search engine in the world, including google and msdn, know how to look for it. I believe the internal MSFT slang for these things, btw, is "nuggets." — i_am_jorf, Sep 08 '09 at 15:02
Dup: http://stackoverflow.com/questions/197047/what-is-the-difference-between-and — Richard, Sep 08 '09 at 16:33
Dup also: http://stackoverflow.com/questions/942166/c-mvc-what-is-the-difference-between-and — Alex, Sep 09 '09 at 01:47

score 35 · Accepted Answer · answered Sep 08 '09 at 12:47

35

<% %> is a generic code block.

<%= expression %> is equivalent to <% Response.Write(expression); %>.

answered Sep 08 '09 at 12:47

mmx

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score 9 · Answer 2 · answered Sep 08 '09 at 13:24

9

Mehrdad's comment about <%$ piqued my curiosity, so I found this inline asp.net tags list by googling "asp.net inline code" (sans quotes). It has msdn links and descriptions of all the inline tags (<%, <%=, <%#, <%$, <%@, <%--).

answered Sep 08 '09 at 13:24

Brian

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to complement, ` – mmx Sep 08 '09 at 13:38
@MehrdadAfshari Not heard of ` – user692942 Mar 15 '16 at 13:24
` – Brian Mar 15 '16 at 21:27

David Andres · Answer 3 · 2009-09-08T13:49:22.047

8

It is confusing, and it takes a good deal of repetition to get comfortable with.

The <%= syntax is used for evaluating expressions whose returned values are intended to be included within HTML markup. For example:

<%= DateTime.Now.ToShortDateString() %>

This will include the current date in the HTML markup.

The <% is for inline statements, where you want to execute one or more commands at a specific point during the page rendering. I've used Html Helpers in the past by executing the helper method using <%. For example,

<% Html.TextBox("txtBox"); %>

Note that the statements used here have to be terminated with a semicolon in C# code.

EDIT: Removed erroneous details about Html helpers and void returns.

edited Sep 08 '09 at 13:49

answered Sep 08 '09 at 12:53

David Andres

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Actually, almost all of the Html Helpers return a string rather than writing to the Response object - . This allows you to e.g. nest helper methods. – Iain Galloway Sep 08 '09 at 12:57
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`` silently discards the return value and doesn't output anything. – mmx Sep 08 '09 at 12:59
Thanks for the clarifications – David Andres Sep 08 '09 at 13:05

score 3 · Answer 4 · answered Sep 08 '09 at 12:49

3

<%= %> tag prints the output of the code in it, <% %> just runs the code.

answered Sep 08 '09 at 12:49

pompo

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score 3 · Answer 5 · edited May 23 '17 at 12:32

This post lists all the varieties nicely: ASP.NET "special" tags.

I would normally post this as a comment but there are a number of other dupes. I recall someone referring to them as "bee stings" (not official terminology) and the keywords I used to search for them were asp.net bee stings.

That said, here are some other dupes:

What is the difference between <% %> and <%= %> in ASP.NET MVC

5 Answers5

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