How to escape brackets in a format string in .Net

Question

How can brackets be escaped in a C# format string so, something like :

String val = "1,2,3"
String.Format(" foo {{0}}", val);

doesn't throw a parse exception but actually outputs the string " foo {1,2,3}"

Is there a way to escape the brackets or should a workaround be used.

Answer 1

Actually your example outputs: foo {0}

For you to output foo {1, 2, 3} you have to do something like:

string t = "1, 2, 3";
string v = String.Format(" foo {{{0}}}", t); ;

To put a { you use {{ and to put a } you use }}.

Answer 2

Almost there! The escape sequence for a brace is {{ or }} so for your example you would use:

string t = "1, 2, 3";
string v = String.Format(" foo {{{0}}}", t);

Answer 3

Doblue open brackets and double closing brackets you can use. But only visible one bracket on your page.

Answer 4

Here is a more generic and far lazier solution to solve your problem:

public static string FormatWithBrackets(this string strObj, params object[] formatParameters)
{
    //  Duplicate the brackets to enable formatting syntax
    var tempStr = strObj.Replace("{", "{{").Replace("}", "}}");

    //  Remove double brackets from formatting arguments
    tempStr = Regex.Replace(tempStr, @"{{(\d+)}}", @"{$1}");

    //  Usual formatting (will also remove the rest of the double brackets)
    return string.Format(tempStr, formatParameters);
}

Of course, this is not performance smart, but it'll fit your need unless you code a Real Time application.

Enjoy.