C# | Verbatim String Literal – @

In C#, a verbatim string is created using a special symbol @. @ is known as a verbatim identifier. If a string contains @ as a prefix followed by double quotes, then compiler identifies that string as a verbatim string and compile that string. The main advantage of @ symbol is to tell the string constructor to ignore escape characters and line breaks.

There is mainly three uses of @ symbol which is as follows:

Use 1: Keyword as an Identifier This symbol allows using a keyword as an identifier.

The @ symbol prefixes the keyword, so the compiler takes keyword as an identifier without any error as shown in the below example: 

Example:

// C# program to illustrate
// the use of @ by using keyword
// as an identifier
using System;
 
public class TECH {
 
    // Main method
    static public void Main()
    {
 
        // Creating and initializing the array
        // here 'for' keyword is used as
        // an identifier by using @ symbol
        string[] @for = {"C#", "PHP", "Java", "Python"};
 
                // as and for keywords is
                // as an identifier
                // using @ symbol
                foreach (string @as in @for)
                {
                    Console.WriteLine("Element of Array: {0}", @as);
                }
    }
}

Output:

Element of Array: C#
Element of Array: PHP
Element of Array: Java
Element of Array: Python

Use 2: For printing the escape sequences in string literals and also using the line breaks etc. in a string literal without any escape sequence. If one will put the escape sequence like “\\” (for backslash), “\u” (Unicode escape sequence), “\x” (hexadecimal escape sequence) etc. in a string literal without using @ symbol then these sequences will be interpreted by compiler automatically. But “” (double quotes) are not interpreted literally. Its like a string interpolation. Let’s see different cases with and without @ symbol.

  • Case: 1
// taking a string literal and 
// try to print double quotes
string str1 = """";

// printing output
// this will give compile
// time error as Unexpected 
// symbol `' 
Console.WriteLine(str1);
  • In the above program, the double quotes inside double quotes as a string literal are interpreted as a single quotation mark.
  • Case: 2
// taking a string literal prefixes
// with @ and try to print double quotes
string str1 = @"""";

// printing output
// this will output as "
Console.WriteLine(str1);
  • In the above program, the output is double quote() not “”
  • Case 3:
// taking a string in which we are storing 
// some location of file but \Testing will 
// interpreted as escape sequence \T 
// similarly \N
string str1 = "\\C:\Testing\New\Target";

// printing str1
// this will give compile time error as
// Unrecognized escape sequence `\T'
// Unrecognized escape sequence `\N'
// Unrecognized escape sequence `\T'
Console.WriteLine(str1);
  • Case 4:
// taking a string and prefix literal with @ symbol. 
// Storing some location of file 
string str1 = @"\\C:\Testing\New\Target";

// printing str1 will give output as 
// \\C:\Testing\New\Target
Console.WriteLine(str1);

Program:

// C# program to illustrate
// the use of @ in terms of
// escape sequences and new
// line and tab
using System;
 
public class TECH {
 
    // Main method
    static public void Main()
    {
 
        // If you use the below commented
        // the part then this will give
        // Unrecognized escape sequence error
        // string S1 = "\\welcome \to TechforTech \ portal \";
        // Console.WriteLine("String 1 is :{0}", S1);
 
        // By using @ in the given string
        // it runs smoothly because
        // @ symbol tells the compiler to
        // ignore all escape sequences
        string S2 = @"\\welcome \to TechforTech \ portal \";
        Console.WriteLine("String 2 is: {0}", S2);
 
        // printing new line character in string literal
        // but it will make the string to break 
        // into a new line, see output
        string S3 = "This is \n C# non verbatim string";
        Console.WriteLine("String 3 is :{0}", S3);
 
        // By using @ symbol /n does not processed
        string S4 = @"This is \n C# verbatim string";
        Console.WriteLine("String 4 is :{0}", S4);
 
        // printing a string literal contains
        // tabs and new line without using
        // any escape sequence
        Console.WriteLine(@"Without Tab Sequence and New Line Character
                               C          C++      Java       Python");
    }
}

Output:

String 2 is: \\welcome \to TechforTech \ portal \
String 3 is :This is 
 C# non verbatim string
String 4 is :This is \n C# verbatim string
Without Tab Sequence and New Line Character
                               C          C++      Java       Python

Chockalingam