What is the difference between <% %> and <%=%>?

Question

What is the difference between <% %> and <%= %> in ASP.NET MVC? And when to use which?

Answer 1

<%= %> writes to the output stream (usually html) while <% %> is for executing arbitrary script code.

Answer 2

Say you have a method on your page, called "SayHello":

protected string SayHello()
{
    return "Hello!";
}

And on your page, you have these statements:

first: <%= SayHello() %>
second: <% SayHello() %>

Your output will be:

first: Hello!
second:

when you use <%= %>, what you put in there is inserted into the html at that position. If you use <% %>, you're just inserting some code into your page.

Answer 3

<%= echos the statement out.

<% just runs it.

Answer 4

See also this question. MVC hasn't changed how these bee-stings work, just how often they're used.

Basically:

• <% - execute code
• <%@ - page directive
• <%$ - resource access
• <%= - explicit output to page
• <%# - data binding
• <%-- - server side comment block

Also new in ASP.Net 4:

• <%: - writes out to the page, but with HTML encoded