How to format a string through String.Format

Question

Numeric

  string a = String.Format("{0:#/#}",12)

output:1/2

But How to Convert it for string Suppose

  String b=String.Format("{0:###-#}","test")

Output : test

Expected Output: tes-t

Answer 1

I think you can split the string to its characters and then use format

string testString = "test";
string formattedString = string.Format("{0}{1}{2}-{3}", testString.Select(c => c.ToString()).ToArray());

Answer 2

You can't format a string through string.Format for the reason that it is already a string.

If you want to manipulate the string, use the methods defined on the string class.