Is_numeric

Imports System.Text

Public Class Form1
    Private Function DoesItMatch (ByVal pInput As String, ByVal pEvaluator As String) As Boolean
        If RegularExpressions.Regex.IsMatch(pInput, pEvaluator) Then
            Return True
        Else
            Return False
        End If
    End Function

    Private Sub MySub()

        'Get the string that we want to evaluate
        Dim strInput As String = TextBox1.Text

        'Is it a number 0 through 9?
        Dim boolIsZeroThroughNine As Boolean = DoesItMatch(strInput, "\b[0-9]\b") 'Note: In VB.NET the beginning & end of a string are denoted with a "\b", where in most other RegEx expressions, it is "^" & "$" respectively.

        If boolIsZeroThroughNine = True Then
            MessageBox.Show("It is 0 through 9")
        Else
            MessageBox.Show("It is NOT 0 through 9")
        End If


        'Or, just check if it is numeric
        Dim boolIsNumeric As Boolean = DoesItMatch(strInput, "\b\d\b") 'I believe the "\d" stands for decimal

        If boolIsNumeric = True Then
            MessageBox.Show("It is numeric")
        Else
            MessageBox.Show("It is NOT numeric")
        End If
    End Sub
End Class

/^\s*[+-]?\d*(\.\d*)?([eE][+-]?\d+)?\s*$/