Detailed explanation of several ways to use @ symbols in C#

1. Qualified strings
The escape character "not" is processed by adding the @ symbol before the string.
If we write a file path, for example, a file under the "D:/text file" path, if the @ symbol is not added, the writing method is as follows:
stringfileName="D://text file//";
It will be easier if you use the @ symbol:
stringfileName=@"D:/text file/";

2. Let the string cross line
Sometimes a string is written in a line very long (such as a SQL statement) without using the @ symbol. One way to write it is like this:

Copy the codeThe code is as follows:

string strSQL="SELECT * FROM  AS e"   
+"INNER  AS c"   3.+"ON ="   4.+"ORDERBY ";   

Add the @ symbol and you can wrap the line directly:

Copy the codeThe code is as follows:

string strSQL=@"SELECT * FROM AS e INNER JOIN AS c ON = ";

3. Usage in identifiers
C# does not allow keywords to be used as identifiers (class names, variable names, method names, tablespace names, etc.), but if @ is added, it will be fine, for example:

Copy the codeThe code is as follows:

namespace @namespace   
{   
  class @class   4.     {   
        public static void @static(int @int)   6.         {   
            if (@int > 0)   8.             {   
                 ("Positive Integer");   10.             }   
            else if (@int == 0)   12.             {   
                 ("Zero");   14.             }   
            else   16.             {   
                 ("Negative Integer");   18.             }   
         }   
     }   
}   