Decimal Narrowing Conversion (Decimal to Double)


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Defines an explicit conversion of a Decimal to a double-precision floating-point number.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

Public Shared Narrowing Operator CType (
	value As Decimal
) As Double


Type: System.Decimal

The value to convert.

Return Value

Type: System.Double

A double-precision floating-point number that represents the converted Decimal.

This operation can result in a loss of precision, because a double-precision floating-point number has fewer significant digits than a Decimal.

This operator supports the explicit conversion of a Decimal to a Double. The syntax for such explicit conversions is language-dependent, and individual language compilers can provide different implementations and return different results. The example illustrates the different return values when you explicitly convert a Decimal value to a Double value by using C#, C++, and Visual Basic. To perform a conversion that is independent of language, you can call the ToDouble or the Convert.ToDouble(Decimal) method.

The following example converts Decimal numbers to Double values by using the explicit Decimal to Double conversion.

Module Example
    Public Sub Main( )
        ' Define an array of Decimal values.
        Dim values() As Decimal= { 0.0000000000000000000000000001d, 
                                   New Decimal(123000000, 0, 0, False, 6),
                                   Decimal.MinValue, Decimal.MaxValue }
        For Each value In values
            Dim dblValue As Double = CDbl(value)
            Console.WriteLine("{0} ({1}) --> {2} ({3})", value,
                              value.GetType().Name, dblValue, 
    End Sub
End Module
' The example displays the following output:
'    0.0000000000000000000000000001 (Decimal) --> 1E-28 (Double)
'    0.0000000000123456789123456789 (Decimal) --> 1.23456789123457E-11 (Double)
'    123 (Decimal) --> 123 (Double)
'    123.000000 (Decimal) --> 123 (Double)
'    123456789.123456789 (Decimal) --> 123456789.123457 (Double)
'    123456789123456789123456789 (Decimal) --> 1.23456789123457E+26 (Double)
'    -79228162514264337593543950335 (Decimal) --> -7.92281625142643E+28 (Double)
'    79228162514264337593543950335 (Decimal) --> 7.92281625142643E+28 (Double)

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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