Visual Basic > Strings

Converting a hex string to a long

Converting a hex string to a long

Below is a routine for converting a hex string to a long.

'Purpose   :    Converts a Hex string value to a long
'Inputs    :    sHex                        The hex value to convert to a long. eg. "H1" or "&H1".
'Outputs   :    Returns the numeric value of a string containing a hex value.
'Notes     :

Public Function CHex(sHex As String) As Long
    Dim iNegative As Integer, sPrefixH As String
    
    On Error Resume Next
    iNegative = CBool(Left$(sHex, 1) = "-")
    sPrefixH = IIf(InStr(1, sHex, "H", vbTextCompare), "", "H")
    
    If iNegative Then
        'Negative number
        If Mid$(sHex, 2, 1) = "&" Then
            CHex = CLng("&" & sPrefixH & Mid$(sHex, 3)) * iNegative
        Else
            'Append the ampersand to enable CLng to convert the value
            CHex = CLng("&" & sPrefixH & Mid$(sHex, 2)) * iNegative
        End If
    Else
        'Positive number
        If Left$(sHex, 1) = "&" Then
            CHex = CLng("&" & sPrefixH & Mid$(sHex, 2))
        Else
            'Append the ampersand to enable CLng to convert the value
            CHex = CLng("&" & sPrefixH & sHex)
        End If
    End If
End Function