How do I format to only include decimal if there are any

Question

What is the best way to format a decimal if I only want decimal displayed if it is not an integer.

Eg:

decimal amount = 1000M
decimal vat = 12.50M


        

Answer 1

    decimal one = 1000M;
    decimal two = 12.5M;

    Console.WriteLine(one.ToString("0.##"));
    Console.WriteLine(two.ToString("0.##"));

Answer 2

Updated following comment by user1676558

Try this:

decimal one = 1000M;    
decimal two = 12.5M;    
decimal three = 12.567M;    
Console.WriteLine(one.ToString("G"));    
Console.WriteLine(two.ToString("G"));
Console.WriteLine(three.ToString("G"));

For a decimal value, the default precision for the "G" format specifier is 29 digits, and fixed-point notation is always used when the precision is omitted, so this is the same as "0.#############################".

Unlike "0.##" it will display all significant decimal places (a decimal value can not have more than 29 decimal places).

The "G29" format specifier is similar but can use scientific notation if more compact (see Standard numeric format strings).

Thus:

decimal d = 0.0000000000000000000012M;
Console.WriteLine(d.ToString("G"));  // Uses fixed-point notation
Console.WriteLine(d.ToString("G29"); // Uses scientific notation