Distinguish between whole and decimal numbers.
Use type called double for decimal numbers.
using System; class Program/*from w w w . j a va2 s. c o m*/ { static void Main(string[] args) { double piApproximately = 3.14; // Pi is already available in C# double piMorePrecisely = Math.PI; // Decimal numbers have always limited precision double notCompletelyOne = 0.999999999999999999; // Outputs Console.WriteLine("Pi value from our code: " + piApproximately); Console.WriteLine("Pi value from C#: " + piMorePrecisely); Console.WriteLine("This should not be exact one: " + notCompletelyOne); } }
You always need to use a decimal point as a separator between the integer and decimal parts of a number.
decimal numbers do not have infinite precision. They are rounded after approximately 15 significant digits.