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What's the use/meaning of the @ character in variable names in C#?
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?
This question is related to
c#
variables
naming
specifications
reserved-words
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; }
}
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"
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.
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"
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; }
}
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.
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; }
}
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.
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; }
}
Source: Stackoverflow.com