Formatting : Zero / Digit placeholder

0 and # are format characters to create custom numeric format strings.

Example :

         double myDouble = 33.945;

 

         Console.WriteLine(myDouble.ToString("#.0000")); //Output = 33.9450

         Console.WriteLine(myDouble.ToString("#.####")); //Output = 33.945

 

         Console.WriteLine(myDouble.ToString("000")); //Output = 034

         Console.WriteLine(myDouble.ToString("###")); //Output = 34

The overloaded ToString-method converts the double to its equivalent string representation, using the specified format.

• Zero placeholder [0]
  In the first example the zero placeholders after the comma make sure that there are 4 digits printed in the output. Example 3 shows padding at the other side.
• Digit placeholder [#]
  This specifier never displays the '0' character if no significant digit is in place (no padding). See example 2 and 4.

You can also use the format string to display other objects (for example a DateTime).

         DateTime dt = DateTime.Now;

         Console.WriteLine(dt.ToString("dddd d MMMM yyyy"));

Interesting links for standard/custom formatting :

• Standard numeric format strings
• Custom numeric format strings
• Standard date format strings
• Custom date format strings
• Enumeration format strings