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Decimal.Round Method (Decimal, Int32)

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

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

public static decimal Round(
	decimal d,
	int decimals
)

Parameters

d
Type: System.Decimal

A decimal number to round.

decimals
Type: System.Int32

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

Return Value

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

ExceptionCondition
ArgumentOutOfRangeException

decimals is not a value from 0 to 28.

This method is equivalent to calling the Round(Decimal, Int32, MidpointRounding) method with a mode argument of MidpointRounding.ToEven.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. It minimizes rounding errors that result from consistently rounding a midpoint value in a single direction.

The following code example rounds several Decimal values to a specified number of decimal places using the Round method.

// 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
*/

.NET Framework

Supported in: 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

Obsolete (compiler warning) in Portable Class Library

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, 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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