Visual Basic

dilkonika wrote:

have to use a kind of data type that accept digits after decimal point.

static void Main(string[] args)
{
    float x = 12345678.33f;

    Console.WriteLine(string.Format("{0:N8}", x));
}

MSDN wrote:

The Decimal[^] value type represents decimal numbers ranging from positive 79,228,162,514,264,337,593,543,950,335 to negative 79,228,162,514,264,337,593,543,950,335. The Decimal value type is appropriate for financial calculations that require large numbers of significant integral and fractional digits and no round-off errors. The Decimal type does not eliminate the need for rounding. Rather, it minimizes errors due to rounding. For example, the following code produces a result of 0.9999999999999999999999999999 instead of 1.

VB

Dim dividend As Decimal = Decimal.One
Dim divisor As Decimal = 3
' The following displays 0.9999999999999999999999999999 to the console
Console.WriteLine(dividend/divisor * divisor)

MSDN wrote:

The Double[^] value type represents a double-precision 64-bit number with values ranging from negative 1.79769313486232e308 to positive 1.79769313486232e308, as well as positive or negative zero, PositiveInfinity, NegativeInfinity, and not a number (NaN). It is intended to represent values that are extremely large (such as distances between planets or galaxies) or extremely small (the molecular mass of a substance in kilograms) and that often are imprecise (such as the distance from earth to another solar system), The Double type complies with the IEC 60559:1989 (IEEE 754) standard for binary floating-point arithmetic.

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

dilkonika wrote:

I need to choose between float and decimal.

Module Module1

   Sub Main()
     Dim f As  Single = 123456792.0F
     Dim fsw As New Stopwatch
     fsw.Start()
     For i =  1 To 100000000
       f *= 1.00000012F
     Next
     fsw.Stop()

     Dim dsw As New Stopwatch
     dsw.Start()
     Dim d As  Decimal = 123456792.0F
     For i =  1 To 100000000
       d *= 1.00000012F
     Next
     dsw.Stop()

     Console.WriteLine(f)
     Console.WriteLine("Float (ms): " & fsw.ElapsedMilliseconds)
     Console.WriteLine(d)
     Console.WriteLine("Decimal (ms): " & dsw.ElapsedMilliseconds)
     Console.WriteLine("Float is " & dsw.ElapsedMilliseconds / fsw.ElapsedMilliseconds  & " faster")

     Console.ReadLine()
   End Sub

End Module

dilkonika wrote:

ok , I understand why I should never choose float.

dilkonika wrote:

But why I should not choose decimal ?

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

Quote:

..it is slower than the non-so-precise float

Quote:

Still accounting in cents makes more sense; as it is the mimimal nondivisible amount that the value can change.

Quote:

Sadly, the .NET decimal does not fit enterely into a SQL decimal

Quote:

but what about values like 2.672