Formatted string literals in C#

To format string literals in C#, use the String.Format method.

In the following example, 0 is the index of the object whose string value gets inserted at that particular position −

using System;
namespace Demo {
   class Test {
      static void Main(string[] args) {
         decimal A = 15.2 m;
         string res = String.Format("Temperature = {0}°C.", A);
         Console.WriteLine(res);
      }
   }
}

In the following example, let us format string for double type.

Example

using System;
class Demo {
   public static void Main(String[] args) {
      Console.WriteLine("Three decimal places...");

      Console.WriteLine( String.Format("{0:0.000}", 987.383));
      Console.WriteLine( String.Format("{0:0.000}", 987.38));
      Console.WriteLine(String.Format("{0:0.000}", 987.7899));

      Console.WriteLine("Thousands Separator...");
      Console.WriteLine(String.Format("{0:0,0.0}", 54567.46));
      Console.WriteLine(String.Format("{0:0,0}", 54567.46));
   }
}

Output

Three decimal places...
987.383
987.380
987.790
Thousands Separator...
54,567.5
54,567