{"id":1294,"date":"2023-03-31T07:54:07","date_gmt":"2023-03-31T00:54:07","guid":{"rendered":"https:\/\/csharptutorial.net\/?page_id=1294"},"modified":"2023-03-31T08:05:40","modified_gmt":"2023-03-31T01:05:40","slug":"csharp-raw-string","status":"publish","type":"page","link":"https:\/\/www.csharptutorial.net\/csharp-tutorial\/csharp-raw-string\/","title":{"rendered":"C# Raw String"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn about C# raw string literals that have been introduced in C# 11.<\/p>\n\n\n\n

Introduction to the C# raw strings<\/h2>\n\n\n\n

C# string literals require escaping of special characters and delimiters. Therefore, it’s difficult to construct literal strings specially for regexes as well as XML and JSON. For example:<\/p>\n\n\n

var<\/span> path = \"C:\\temp\\no.txt\"<\/span>;\r\n\r\nConsole.WriteLine(path);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example, the \\t<\/code> means tab and \\n<\/code> means new line. It outputs the following to the console:<\/p>\n\n\n
C<\/span>:      emp<\/span>\r\no<\/span>.txt<\/span><\/code><\/span>Code language:<\/span> CSS<\/span> (<\/span>css<\/span>)<\/span><\/small><\/pre>\n\n\n
To fix it, you need to use a verbatim string by prefixing the string with the @<\/code> character:<\/p>\n\n\n
var<\/span> path = @\"C:\\temp\\no.txt\"<\/span>;\r\n\r\nConsole.WriteLine(path);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
Also, if a string contains quotes \"<\/code>, you need to escape it using the \\<\/code> characters. For example:<\/p>\n\n\n
var<\/span> response = \"{ \\\"name\\\": \\\"John Doe\\\"}\"<\/span>;\nConsole.WriteLine(response);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
The string becomes difficult to read.<\/p>\n\n\n\n
C# 11 introduced raw string to overcome the problems. A raw string uses a flexible start and end delimiter to avoid conflict with the contents of the string.<\/p>\n\n\n\n
A raw string starts with a minimum of three quotes \"\"\"<\/code> and is optionally followed by a new line, the content of the string, and ends with the same number of quotes.<\/p>\n\n\n\n
For example:<\/p>\n\n\n
var<\/span> json = \"\"<\/span>\"{ \"<\/span>name\": \"<\/span>John Doe\"}\"<\/span>\"\"<\/span>;\r\nConsole.WriteLine(json);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
{ \"name\"<\/span>: \"John Doe\"<\/span>}<\/code><\/span>Code language:<\/span> JSON \/ JSON with Comments<\/span> (<\/span>json<\/span>)<\/span><\/small><\/pre>\n\n\n
If the string itself may use three quotes then the raw string can have longer starting\/ending delimiters, which are four quotes like this:<\/p>\n\n\n
var<\/span> s = \"\"<\/span>\"\"<\/span> C# raw string uses a minimum of \"\"\"  \"\"\"\";<\/span>\r\nConsole.WriteLine(s);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
C# raw string uses a minimum of \"\"\"<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Multi-line raw string literals<\/h3>\n\n\n\n
C# raw string literals support multiline strings. For example:<\/p>\n\n\n
var<\/span> json = \"\"<\/span>\"\r\n    { \r\n        \"<\/span>name\": \"<\/span>John Doe\",\r\n        \"<\/span>address\": {\r\n            \"<\/span>home\": \"<\/span>4000<\/span> N. 1<\/span>st street\",\r\n            \"<\/span>work\": \"<\/span>101<\/span> N. 1<\/span>st street\"\r\n        }\r\n    }\r\n    \"<\/span>\"\"<\/span>;\r\nConsole.WriteLine(json);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
{\r\n    \"name\"<\/span>: \"John Doe\"<\/span>,\r\n    \"address\"<\/span>: {\r\n        \"home\"<\/span>: \"4000 N. 1st street\"<\/span>,\r\n        \"work\"<\/span>: \"101 N. 1st street\"<\/span>\r\n    }\r\n}<\/code><\/span>Code language:<\/span> JSON \/ JSON with Comments<\/span> (<\/span>json<\/span>)<\/span><\/small><\/pre>\n\n\n
The multi-line raw string literals follow these rules:<\/p>\n\n\n\n
    \n
  • The opening and closing quotes of a multi-line raw string literal must be on separate lines.<\/li>\n\n\n\n
  • Any whitespace following the opening quote on the same line is ignored.<\/li>\n\n\n\n
  • Whitespace-only lines following the opening quotes are included in the string literal.<\/li>\n\n\n\n
  • Any whitespace to the left of the closing quotes is removed from all lines of the raw string literal.<\/li>\n<\/ul>\n\n\n\n
    \"\"<\/figure>\n\n\n\n
    Raw string interpolation <\/h3>\n\n\n\n
    Raw string literals also support string interpolation that replaces the variables and expressions inside the string with their values.<\/p>\n\n\n\n
    The following example causes an error because of unexpected {}<\/code> in JSON format:<\/p>\n\n\n
    var<\/span> name = \"John Doe\"<\/span>;\r\nvar<\/span> json = $\"\"<\/span>\" {\"<\/span>Name\": \"<\/span>{name}\" } \"<\/span>\"\"<\/span>;\r\n\r\nConsole.WriteLine(json);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
    To fix this, you need to surround the variable with double opening and closing curly braces {{}}<\/code>. Also, you need to use double $$<\/code> characters:<\/p>\n\n\n
    var<\/span> name = \"John Doe\"<\/span>;\r\nvar<\/span> json = $$\"\"<\/span>\" { \"<\/span>Name\": \"<\/span>{{name}}\" } \"<\/span>\"\"<\/span>;\r\n\r\nConsole.WriteLine(json);<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
    Output:<\/p>\n\n\n
    { \"Name\"<\/span>: \"John Doe\"<\/span> }<\/code><\/span>Code language:<\/span> JSON \/ JSON with Comments<\/span> (<\/span>json<\/span>)<\/span><\/small><\/pre>\n\n\n
    Summary<\/h2>\n\n\n\n
      \n
    • Use a minimum of opening and closing \"\"\"<\/code> to form a raw string literal.<\/li>\n\n\n\n
    • C# raw string literals support multi-line strings and interpolations.<\/li>\n<\/ul>\n
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