Information.IsNumeric Method
Returns a Boolean value indicating whether an expression can be evaluated as a number.
Namespace: Microsoft.VisualBasic
Assembly: Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)
Parameters
- Expression
- Type: System.Object
Required. Object expression.
Return Value
Type: System.BooleanReturns a Boolean value indicating whether an expression can be evaluated as a number.
IsNumeric returns True if the data type of Expression is Boolean, Byte, Decimal, Double, Integer, Long, SByte, Short, Single, UInteger, ULong, or UShort. It also returns True if Expression is a Char, String, or Object that can be successfully converted to a number. Expression can contain non-numeric characters. IsNumeric returns True if Expression is a string that contains a valid hexadecimal or octal number. IsNumeric also returns True if Expression contains a valid numeric expression that begins with a + or - character or contains commas.
IsNumeric returns False if Expression is of data type Date. It returns False if Expression is a Char, String, or Object that cannot be successfully converted to a number.
The following example uses the IsNumeric function to determine if the contents of a variable can be evaluated as a number.
Dim testVar As Object Dim numericCheck As Boolean testVar = "53" ' The following call to IsNumeric returns True. numericCheck = IsNumeric(testVar) testVar = "459.95" ' The following call to IsNumeric returns True. numericCheck = IsNumeric(testVar) testVar = "45 Help" ' The following call to IsNumeric returns False. numericCheck = IsNumeric(testVar)
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.
