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Decimal.Round Method

Rounds a Decimal value to a specified number of decimal places.

[Visual Basic]
Public Shared Function Round( _
   ByVal d As Decimal, _
   ByVal decimals As Integer _
) As Decimal
[C#]
public static decimal Round(
 decimal d,
 int decimals
);
[C++]
public: static Decimal Round(
 Decimal d,
 int decimals
);
[JScript]
public static function Round(
   d : Decimal,
 decimals : int
) : Decimal;

Parameters

d
A Decimal value to round.
decimals
A value from 0 to 28 that specifies the number of decimal places to round to.

Return Value

The Decimal number equivalent to d rounded to decimals number of decimal places.

Exceptions

Exception Type Condition
ArgumentOutOfRangeException decimals is not a value from 0 to 28.

Remarks

When d is exactly halfway between two rounded values, the result is the rounded value that has an even digit in the far right decimal position. For example, when rounded to two decimals, the value 2.345 becomes 2.34 and the value 2.355 becomes 2.36. This process is known as rounding toward even, or rounding to nearest.

Example

[Visual Basic, C#, C++] The following code example rounds several Decimal values to a specified number of decimal places using the Round method.

[Visual Basic] 
' Example of the Decimal.Round method. 
Imports System
Imports Microsoft.VisualBasic

Module DecimalRoundDemo
    
    Const dataFmt As String = "{0,26}{1,8}{2,26}"

    ' Display Decimal.Round parameters and the result.
    Sub ShowDecimalRound( Argument As Decimal, Digits As Integer )

        Dim rounded As Decimal = Decimal.Round( Argument, Digits )

        Console.WriteLine( dataFmt, Argument, Digits, rounded )
    End Sub

    Sub Main( )
        Console.WriteLine( "This example of the " & _
            "Decimal.Round( Decimal, Integer ) " & vbCrLf & _
            "method generates the following output." & vbCrLf )
        Console.WriteLine( dataFmt, "Argument", "Digits", "Result" )
        Console.WriteLine( dataFmt, "--------", "------", "------" )

        ' Create pairs of Decimal objects.
        ShowDecimalRound( 1.45D, 1 ) 
        ShowDecimalRound( 1.55D, 1 ) 
        ShowDecimalRound( 123.456789D, 4 ) 
        ShowDecimalRound( 123.456789D, 6 ) 
        ShowDecimalRound( 123.456789D, 8 ) 
        ShowDecimalRound( -123.456D, 0 ) 
        ShowDecimalRound( _
            New Decimal( 1230000000, 0, 0, True, 7 ), 3 )
        ShowDecimalRound( _
            New Decimal( 1230000000, 0, 0, True, 7 ), 11 )
        ShowDecimalRound( -9999999999.9999999999D, 9 )
        ShowDecimalRound( -9999999999.9999999999D, 10 )
    End Sub
End Module 

' This example of the Decimal.Round( Decimal, Integer )
' method generates the following output.
'
'                  Argument  Digits                    Result
'                  --------  ------                    ------
'                      1.45       1                       1.4
'                      1.55       1                       1.6
'                123.456789       4                  123.4568
'                123.456789       6                123.456789
'                123.456789       8                123.456789
'                  -123.456       0                      -123
'              -123.0000000       3                  -123.000
'              -123.0000000      11              -123.0000000
'    -9999999999.9999999999       9    -10000000000.000000000
'    -9999999999.9999999999      10    -9999999999.9999999999

[C#] 
// Example of the decimal.Round method. 
using System;

class DecimalRoundDemo
{
    const string dataFmt = "{0,26}{1,8}{2,26}";

    // Display decimal.Round parameters and the result.
    public static void ShowDecimalRound( decimal Argument, int Digits )
    {
        decimal rounded = decimal.Round( Argument, Digits );

        Console.WriteLine( dataFmt, Argument, Digits, rounded );
    }

    public static void Main( )
    {
        Console.WriteLine( "This example of the " +
            "decimal.Round( decimal, Integer ) \n" +
            "method generates the following output.\n" );
        Console.WriteLine( dataFmt, "Argument", "Digits", "Result" );
        Console.WriteLine( dataFmt, "--------", "------", "------" );

        // Create pairs of decimal objects.
        ShowDecimalRound( 1.45M, 1 );
        ShowDecimalRound( 1.55M, 1 );
        ShowDecimalRound( 123.456789M, 4 );
        ShowDecimalRound( 123.456789M, 6 );
        ShowDecimalRound( 123.456789M, 8 );
        ShowDecimalRound( -123.456M, 0 );
        ShowDecimalRound( 
            new decimal( 1230000000, 0, 0, true, 7 ), 3 );
        ShowDecimalRound( 
            new decimal( 1230000000, 0, 0, true, 7 ), 11 );
        ShowDecimalRound( -9999999999.9999999999M, 9 );
        ShowDecimalRound( -9999999999.9999999999M, 10 );
    }
}

/*
This example of the decimal.Round( decimal, Integer )
method generates the following output.

                  Argument  Digits                    Result
                  --------  ------                    ------
                      1.45       1                       1.4
                      1.55       1                       1.6
                123.456789       4                  123.4568
                123.456789       6                123.456789
                123.456789       8                123.456789
                  -123.456       0                      -123
              -123.0000000       3                  -123.000
              -123.0000000      11              -123.0000000
    -9999999999.9999999999       9    -10000000000.000000000
    -9999999999.9999999999      10    -9999999999.9999999999
*/

[C++] 
// Example of the Decimal::Round method. 
#using <mscorlib.dll>
using namespace System;

const __wchar_t* dataFmt = L"{0,26}{1,8}{2,26}" ;

// Display Decimal::Round parameters and the result.
void ShowDecimalRound( Decimal Argument, int Digits )
{
    Decimal rounded = Decimal::Round( Argument, Digits );

    Console::WriteLine( dataFmt, __box( Argument ), 
        __box( Digits ), __box( rounded ) );
}

void main( )
{
    Console::WriteLine( S"This example of the " 
        S"Decimal::Round( Decimal, Integer ) \n" 
        S"method generates the following output.\n" );
    Console::WriteLine( dataFmt, S"Argument", S"Digits", S"Result" );
    Console::WriteLine( dataFmt, S"--------", S"------", S"------" );

    // Create pairs of Decimal objects.
    ShowDecimalRound( Decimal::Parse( S"1.45" ), 1 );
    ShowDecimalRound( Decimal::Parse( S"1.55" ), 1 );
    ShowDecimalRound( Decimal::Parse( S"123.456789" ), 4 );
    ShowDecimalRound( Decimal::Parse( S"123.456789" ), 6 );
    ShowDecimalRound( Decimal::Parse( S"123.456789" ), 8 );
    ShowDecimalRound( Decimal::Parse( S"-123.456" ), 0 );
    ShowDecimalRound( Decimal( 1230000000, 0, 0, true, 7 ), 3 );
    ShowDecimalRound( Decimal( 1230000000, 0, 0, true, 7 ), 11 );
    ShowDecimalRound( 
        Decimal::Parse( S"-9999999999.9999999999" ), 9 );
    ShowDecimalRound( 
        Decimal::Parse( S"-9999999999.9999999999" ), 10 );
}

/*
This example of the Decimal::Round( Decimal, Integer )
method generates the following output.

                  Argument  Digits                    Result
                  --------  ------                    ------
                      1.45       1                       1.4
                      1.55       1                       1.6
                123.456789       4                  123.4568
                123.456789       6                123.456789
                123.456789       8                123.456789
                  -123.456       0                      -123
              -123.0000000       3                  -123.000
              -123.0000000      11              -123.0000000
    -9999999999.9999999999       9    -10000000000.000000000
    -9999999999.9999999999      10    -9999999999.9999999999
*/

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, .NET Compact Framework, Common Language Infrastructure (CLI) Standard

See Also

Decimal Structure | Decimal Members | System Namespace | Floor | Truncate

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