What's the use/meaning of the @ character in variable names in C#?

Question

I discovered that you can start your variable name with a \'@\' character in C#. In my C# project I was using a web service (I added a web reference to my project) that was

Answer 1

You can use it to use the reserved keywords as variable name like

 int @int = 3; 

the compiler will ignores the @ and compile the variable as int

it is not a common practice to use thought

Answer 2

Another use case are extension methods. The first, special parameter can be distinguished to denote its real meaning with @this name. An example:

public static TValue GetValueOrDefault<TKey, TValue>(
    this IDictionary<TKey, TValue> @this,
    TKey key,
    TValue defaultValue)
    {
        if (!@this.ContainsKey(key))
        {
            return defaultValue;
        }

        return @this[key];
    }

Answer 3

If we use a keyword as the name for an identifier, we get a compiler error “identifier expected, ‘Identifier Name’ is a keyword” To overcome this error, prefix the identifier with “@”. Such identifiers are verbatim identifiers. The character @ is not actually part of the identifier, so the identifier might be seen in other languages as a normal identifier, without the prefix