How to escape braces (curly brackets) in a format string in .NET

How can brackets be escaped in using string.Format?

For example:

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

This example doesn't throw an exception, but it outputs the string foo {0}.

Is there a way to escape the brackets?

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 output a { you use {{ and to output a } you use }}.

Or now, you can also use C# string interpolation like this (a feature available in C# 6.0)

Escaping brackets: String interpolation $(""). It is new feature in C# 6.0.

var inVal = "1, 2, 3";
var outVal = $" foo {{{inVal}}}";
// The output will be:  foo {1, 2, 3}

Stack Overflow Q#91362, score: 1504