What does "@" mean in C# [duplicate]

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Possib开发者_开发百科le Duplicate:

when to use @ in c# ?

F.e. string sqlSelect = @"SELECT * FROM Sales".

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It means interpret the following string as literal. Meaning, the \ in the string will actually be a "\" in the output, rather than having to put "\\" to mean the literal character

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Before string it allows different string formating rules. You can't use backslash to specify special symbols and "" (double quotes become quotes). I find this format very useful for regular expressions

Example

Console.WriteLine(@"\n""\/a"); // outputs \n"\/a 
Console.WriteLine("\\n\"\"\\/a"); // outputs \n"\/a

You might also seen @ symbol before variable. In such case it allows using special C# keywords as variables.

Example:

var @switch = 1;
var @if = "test";

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It means there is no need to escape characters in such a string.

So if you want to write the path for c:\Windows, you can write it as

string path = "c:\\Windows";  // Note escaped '\'

OR

string path = @"c:\Windows";  // '\' need not be escaped

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There are two types of string literals, regular and verbatim. The @ symbol makes it a verbatim string literal.

MSDN: String literals (C#)

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In C and C++, string has some special characters called "escape characters". For example \, & and the " itself is an escape character!

In the very normal way, you to print a statement like:

Nancy Said Hello World! & smiled

you had to set your string like next

string str = "Nancy said Hello World! \& smiled.";

But people in Microsoft made a new cool feature in C# compiler so you can escape the headache of handling the escape characters by adding @ before any string, and the compiler will handle all the escape characters for you by himself. For the last example you can have this in C# like next:

string str = @"Nancy said Hello World! & smiled.";

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Verbatim string literals start with @ and are also enclosed in double quotation marks. For example:

@"good morning"  // a string literal

Nicked from, have a look at the last few lines above the example for more information. http://msdn.microsoft.com/en-us/library/362314fe.aspx

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Used for string literal. It marks the string within the quote (") marks as the value without applying any interpretation for symbols in that string.

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It allows you to have a string with a \ delimiter in it. @"C:\A\b\c\d\e\f" is legal.