Why do people use an @ sign before a string?

Alan Silver · Mar 9, 2005

Hello,

I have noticed in a few bits of code that people sometimes do things
like...

SomeFunction(@"a text string");

What is the purpose of the @ sign? I have seen it most when passing
connection strings (admittedly in example code, as connection strings
would be better stored elsewhere in a real app), but I don't think it's
related to that.

Anyone care to enlighten me? TIA

Guest · Mar 9, 2005

The @ can shorten typing, as it states "This string is a literal". Example of
two equivalent strings:

string URL = @"http://msnd.microsoft.com/newsgroups";
string URL = "http:////msdn.microsoft.com//newsgroups";

In the second string, every whack has to be escaped.

---

Gregory A. Beamer
MVP; MCP: +I, SE, SD, DBA

***************************
Think Outside the Box!
***************************

Alan Silver · Mar 9, 2005

The @ can shorten typing, as it states "This string is a literal". Example of

two equivalent strings:

string URL = @"http://msnd.microsoft.com/newsgroups";
string URL = "http:////msdn.microsoft.com//newsgroups";

In the second string, every whack has to be escaped.

Ooh, ain't that clever!! I'm not sure why you need to double the / in
the second example though, is it used for something special? I thought
the backslash was, say for embedding a newline character.

How about embedding quotes, would this help?

Thanks for the reply.

***************************
Think Outside the Box!

When I grow big enough to see over the top, I'll try thinking!!

William F. Robertson, Jr. · Mar 9, 2005

Yes, you are correct. I am sure Gregory meant that. Those should have been
backspaces such as a unc path.

You were asking about escaping string.

string s = "He said, \"No!\"";
string s = @"He said, ""No!""";

Notice the double double quotes.

bill

Matt Berther · Mar 9, 2005

Hello Alan,

@ means to take the string literally...

Take for example a file path:

string file = "c:\temp\foo.xml";

This will not be valid, since \t is actually a tab character. So, you have
a choice of either doing this:

string file = "c:\\temp\\foo.xml";

or

string file = @"c:\temp\foo.xml";

Alan Silver · Mar 9, 2005

Yes, you are correct. I am sure Gregory meant that. Those should have been

backspaces such as a unc path.

You were asking about escaping string.

string s = "He said, \"No!\"";
string s = @"He said, ""No!""";

Notice the double double quotes.

But what do you gain in this case? You have substituted one escape
character for another. My first impression was that you could type a
string without escape characters at all. Your example doesn't give any
benefit for having the @.

Apart from string containing backslashes, is there any benefit of the @
notation?

Thanks for the reply

bill

darrel · Mar 9, 2005

string file = "c:\temp\foo.xml";

This will not be valid, since \t is actually a tab character. So, you have
a choice of either doing this:

Is that in all of the .net languages or just some? I believe I am passing
all sorts of file paths with backslashes as strings without the @ in vb.net.
Maybe I just have been lucky and haven't stumbled on a 'slash caracter' pair
that's actually an escape of something?

-Darrel

Alan Silver · Mar 9, 2005

Thanks Matt, that's a good example.

Hello Alan,

@ means to take the string literally...

Take for example a file path:

string file = "c:\temp\foo.xml";

This will not be valid, since \t is actually a tab character. So, you
have a choice of either doing this:

string file = "c:\\temp\\foo.xml";

or

string file = @"c:\temp\foo.xml";

bruce barker · Mar 9, 2005

its a c# feature (i forget what language c# stole it from). vb does not use
\ as a quote char. beside making it easier to build filename straings, it
also allows the newline character so you can do:

string html =
@"<html>
<body>
</body>
</html>
";

-- bruce (sqlwork.com)

| > string file = "c:\temp\foo.xml";
| >
| > This will not be valid, since \t is actually a tab character. So, you
have
| > a choice of either doing this:
|
| Is that in all of the .net languages or just some? I believe I am passing
| all sorts of file paths with backslashes as strings without the @ in
vb.net.
| Maybe I just have been lucky and haven't stumbled on a 'slash caracter'
pair
| that's actually an escape of something?
|
| -Darrel
|
|

William F. Robertson, Jr. · Mar 9, 2005

Oh, you can also do this.

string script = @"
<script language=""javascript"">
function myFunction()
{
alert( 'hello world' );
}
";

or
string script = String.Format( @"
<script language=""javascript"">
function myFunction()
{
alert( document.all[""{0}""].value );
}
", myControl.ID );

It makes it more readable, it is purely a personal preference, so if you
don't want to use it, then don't. I use both with a '@' and without
depending on my usage and what I am going for.

string uncPath = "\\\\server1\\share\directory\\file.txt"
string uncPath = @\\server1\share\directory\file.txt

bill

Alan Silver said:
Yes, you are correct. I am sure Gregory meant that. Those should have been
backspaces such as a unc path.

You were asking about escaping string.

string s = "He said, \"No!\"";
string s = @"He said, ""No!""";

Notice the double double quotes.

Click to expand...

But what do you gain in this case? You have substituted one escape
character for another. My first impression was that you could type a
string without escape characters at all. Your example doesn't give any
benefit for having the @.

Apart from string containing backslashes, is there any benefit of the @
notation?

Thanks for the reply

Alan Silver · Mar 9, 2005

Oh, you can also do this.

Now that's *really* clever!! Thanks for pointing it out.

string script = @"
<script language=""javascript"">
function myFunction()
{
alert( 'hello world' );
}
";

or
string script = String.Format( @"
<script language=""javascript"">
function myFunction()
{
alert( document.all[""{0}""].value );
}
", myControl.ID );

It makes it more readable, it is purely a personal preference, so if you
don't want to use it, then don't. I use both with a '@' and without
depending on my usage and what I am going for.

string uncPath = "\\\\server1\\share\directory\\file.txt"
string uncPath = @\\server1\share\directory\file.txt

bill

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Why do people use an @ sign before a string?

Alan Silver

Guest

Alan Silver

William F. Robertson, Jr.

Matt Berther

Alan Silver

darrel

Alan Silver

bruce barker

William F. Robertson, Jr.

Alan Silver

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