# VB.NET Math.Ceiling and Floor: Double Examples

Use the Math.Ceiling and Math.Floor methods to compute ceiling and floors of Doubles.**Math.Ceiling, Floor.** Often numbers need to be manipulated. We can round a number upwards to the nearest integer (with a ceiling function), or down with a floor function.

**With VB.NET methods,** these functions are available without any development work. We invoke Math.Ceiling and Floor, often with Doubles with fractional parts.

Double

**Ceiling example.** To begin we use the Math.Ceiling function. We pass in Double values and Ceiling returns a Double. Ceiling always changes a fractional value to be the higher integer.

**And:** With negative and positive numbers, this is not changed. The ceiling of -1.23 is -1.

**VB.NET program that computes ceiling, uses Math.Ceiling**
Module Module1
Sub Main()*
' Ceiling returns the next highest integer if a fraction part exists.
*Dim result As Double = __Math.Ceiling__(1.23)
Console.WriteLine(*"CEILING 1.23: "* + result.ToString)
Dim result2 As Double = Math.Ceiling(-1.23)
Console.WriteLine(*"CEILING -1.23: "* + result2.ToString)
Dim result3 As Double = Math.Ceiling(1)
Console.WriteLine(*"CEILING 1: "* + result3.ToString)
End Sub
End Module
**Output**
CEILING 1.23: 2
CEILING -1.23: -1
CEILING 1: 1

**Floor example.** With floor, we change a number with a fractional part to be the lower integer. Even a number like 1.99 is changed to 1. And integers are left unchanged.

**VB.NET program that computes floor, uses Math.Floor**
Module Module1
Sub Main()*
' Floor changes a number to the lower integer if a fraction part is present.
*Dim floor As Double = __Math.Floor__(1.99)
Console.WriteLine(*"FLOOR 1.99: "* + floor.ToString)
Dim floor2 As Double = Math.Floor(-1.99)
Console.WriteLine(*"FLOOR -1.99: "* + floor2.ToString)
End Sub
End Module
**Output**
FLOOR 1.99: 1
FLOOR -1.99: -2

**A summary.** Ceiling and Floor are important functions in the .NET Framework. We rarely need to implement these mathematical methods—we use the reliable ones contained in the Framework.

© 2007-2020 Sam Allen. Every person is special and unique. Send bug reports to info@dotnetperls.com.