Math.Round Method (Decimal, Int32)
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Rounds a decimal value to a specified number of fractional digits.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared Function Round ( _
d As Decimal, _
decimals As Integer _
) As Decimal
public static decimal Round(
decimal d,
int decimals
)
Parameters
- d
Type: System.Decimal
A decimal number to be rounded.
- decimals
Type: System.Int32
The number of decimal places in the return value.
Return Value
Type: System.Decimal
The number nearest d with a number of fractional digits equal to decimals.
Exceptions
Exception | Condition |
---|---|
ArgumentOutOfRangeException | decimals is less than 0 or greater than 28. |
OverflowException | The result is outside the range of a Decimal. |
Remarks
The decimals parameter specifies the number of fractional digits in the return value and ranges from 0 to 28. If decimals is zero, an integer is returned.
If the value of the digits in d to the right of the decimals position is halfway between the digit in position decimals, that digit is rounded up if it is odd, or left unchanged if it is even. If the precision of d is less than decimals, d is returned unchanged.
The behavior of this method follows IEEE Standard 754, section 4. This kind of rounding is sometimes called rounding to nearest, or banker's rounding. It minimizes rounding errors that result from consistently rounding a midpoint value in a single direction.
Examples
The following example demonstrates rounding to nearest.
Math.Round(3.44, 1) 'Returns 3.4.
Math.Round(3.45, 1) 'Returns 3.4.
Math.Round(3.46, 1) 'Returns 3.5.
Math.Round(4.34, 1) ' Returns 4.3
Math.Round(4.35, 1) ' Returns 4.4
Math.Round(4.36, 1) ' Returns 4.4
Math.Round(3.44, 1); //Returns 3.4.
Math.Round(3.45, 1); //Returns 3.4.
Math.Round(3.46, 1); //Returns 3.5.
Math.Round(4.34, 1); // Returns 4.3
Math.Round(4.35, 1); // Returns 4.4
Math.Round(4.36, 1); // Returns 4.4
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0
XNA Framework
Supported in: Xbox 360, Windows Phone OS 7.0
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.