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}
Yes, to output {
in string.Format
you have to escape it like this: {{
So the following will output "foo {1,2,3}"
.
String val = "1,2,3";
String.Format(" foo {{{0}}}", val);
But you have to know about a design bug in C# which is that by going on the above logic you would assume this below code will print {24.00}:
int i = 24;
string str = String.Format("{{{0:N}}}", i); // Gives '{N}' instead of {24.00}
But this prints {N}. This is because the way C# parses escape sequences and format characters. To get the desired value in the above case, you have to use this instead:
String.Format("{0}{1:N}{2}", "{", i, "}") // Evaluates to {24.00}
Reference Articles
- String.Format gotcha
- String Formatting FAQ