What does the @ symbol before a variable name mean in C#?

Question

I understand that the @ symbol can be used before a string literal to change how the compiler parses the string. But what does it mean when a variable name is prefixed with the @ symbol?

Answer 1

The @ symbol allows you to use reserved word. For example:

int @class = 15;

The above works, when the below wouldn't:

int class = 15;

Answer 2

The @ symbol serves 2 purposes in C#:

Firstly, it allows you to use a reserved keyword as a variable like this:

int @int = 15;

The second option lets you specify a string without having to escape any characters. For instance the '\' character is an escape character so typically you would need to do this:

var myString = "c:\\myfolder\\myfile.txt"

alternatively you can do this:

var myString = @"c:\myFolder\myfile.txt"

Answer 3

An important point that the other answers forgot, is that "@keyword" is compiled into "keyword" in the CIL.

So if you have a framework that was made in, say, F#, which requires you to define a class with a property named "class", you can actually do it.

It is not that useful in practice, but not having it would prevent C# from some forms of language interop.

I usually see it used not for interop, but to avoid the keyword restrictions (usually on local variable names, where this is the only effect) ie.

private void Foo(){
   int @this = 2;
}

but I would strongly discourage that! Just find another name, even if the 'best' name for the variable is one of the reserved names.

Answer 4

It allows you to use a C# keyword as a variable. For example:

class MyClass
{
   public string name { get; set; }
   public string @class { get; set; }
}