Math.Round Method (Double, Int32, MidpointRounding)
Rounds a double-precision floating-point value to a specified number of fractional digits. A parameter specifies how to round the value if it is midway between two numbers.
Assembly: mscorlib (in mscorlib.dll)
static member Round : value:float * digits:int * mode:MidpointRounding -> float
- Type: System.Double
A double-precision floating-point number to be rounded.
- Type: System.Int32
The number of fractional digits in the return value.
- Type: System.MidpointRounding
Specification for how to round value if it is midway between two other numbers.
Return ValueType: System.Double
The number nearest to value that has a number of fractional digits equal to digits. If value has fewer fractional digits than digits, value is returned unchanged.
For examples and comprehensive usage information about this and other overloads of the Round method, see the Round reference page.
Because of the loss of precision that can result from representing decimal values as floating-point numbers or performing arithmetic operations on floating-point values, in some cases the method may not appear to round midpoint values as specified by the mode parameter. This is illustrated in the following example, where 2.135 is rounded to 2.13 instead of 2.14. This occurs because internally the method multiplies value by 10digits, and the multiplication operation in this case suffers from a loss of precision.