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Decimal Constructor (Double)

Initializes a new instance of Decimal to the value of the specified double-precision floating-point number.

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

public Decimal(
	double value
)

Parameters

value
Type: System.Double

The value to represent as a Decimal.

ExceptionCondition
OverflowException

value is greater than MaxValue or less than MinValue.

-or-

value is Double.NaN, Double.PositiveInfinity, or Double.NegativeInfinity.

This constructor rounds value to 15 significant digits using rounding to nearest. This is done even if the number has more than 15 digits and the less significant digits are zero.

The following code example creates several Decimal numbers using the constructor overload that initializes a Decimal structure with a Double value.

// Example of the decimal( double ) constructor. 
using System;

class DecimalCtorDoDemo
{
    // Get the exception type name; remove the namespace prefix. 
    public static string GetExceptionType( Exception ex )
    {
        string exceptionType = ex.GetType( ).ToString( );
        return exceptionType.Substring( 
            exceptionType.LastIndexOf( '.' )+1 );
    }

    // Create a decimal object and display its value. 
    public static void CreateDecimal( double value, string valToStr )
    {
        // Format and display the constructor.
        Console.Write( "{0,-34}", 
            String.Format( "decimal( {0} )", valToStr ) );

        try
        {
            // Construct the decimal value. 
            decimal decimalNum = new decimal( value );

            // Display the value if it was created successfully.
            Console.WriteLine( "{0,31}", decimalNum );
        }
        catch( Exception ex )
        {
            // Display the exception type if an exception was thrown.
            Console.WriteLine( "{0,31}", GetExceptionType( ex ) );
        }
    }

    public static void Main( )
    {
        Console.WriteLine( "This example of the decimal( double ) " +
            "constructor \ngenerates the following output.\n" );
        Console.WriteLine( "{0,-34}{1,31}", "Constructor", 
            "Value or Exception" );
        Console.WriteLine( "{0,-34}{1,31}", "-----------", 
            "------------------" );

        // Construct decimal objects from double values.
        CreateDecimal( 1.23456789E+5, "1.23456789E+5" );
        CreateDecimal( 1.234567890123E+15, "1.234567890123E+15" );
        CreateDecimal( 1.2345678901234567E+25, 
            "1.2345678901234567E+25" );
        CreateDecimal( 1.2345678901234567E+35, 
            "1.2345678901234567E+35" );
        CreateDecimal( 1.23456789E-5, "1.23456789E-5" );
        CreateDecimal( 1.234567890123E-15, "1.234567890123E-15" );
        CreateDecimal( 1.2345678901234567E-25, 
            "1.2345678901234567E-25" );
        CreateDecimal( 1.2345678901234567E-35, 
            "1.2345678901234567E-35" );
        CreateDecimal( 1.0 / 7.0, "1.0 / 7.0" );
    }
}

/*
This example of the decimal( double ) constructor
generates the following output.

Constructor                                    Value or Exception
-----------                                    ------------------
decimal( 1.23456789E+5 )                               123456.789
decimal( 1.234567890123E+15 )                    1234567890123000
decimal( 1.2345678901234567E+25 )      12345678901234600000000000
decimal( 1.2345678901234567E+35 )               OverflowException
decimal( 1.23456789E-5 )                          0.0000123456789
decimal( 1.234567890123E-15 )       0.000000000000001234567890123
decimal( 1.2345678901234567E-25 )  0.0000000000000000000000001235
decimal( 1.2345678901234567E-35 )                               0
decimal( 1.0 / 7.0 )                            0.142857142857143
*/

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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