Asc, AscW Functions
str(required; String or Char)
Any expression that evaluates to a nonempty string
An Integer that represents the character code of the first character of the string. The range for the returned value is 0 - 255 on nonDBCS systems, and -32768 to 32767 on DBCS systems.
Returns an Integer representing the character code for the first character of the string passed to it. All other characters in the string are ignored
The string expression passed to the function must contain at least one character or a runtime error is generated.
Only the first character of the string is evaluated by Asc or AscW.
Dim sChars As String Dim iCharCode As Integer sChars = TextBox1.Text If Len(sChars) > 0 Then iCharCode = Asc(sChars) If iCharCode >= 97 And iChar <= 122 Then MsgBox "The first character must be uppercase" End If End If
Check that the string you are passing to the function contains at least one character using the Len function, as the following example shows:
If Len(sMyString) > 0 Then iCharCode = Asc(sMyString) Else MsgBox("Cannot process a zero-length string") End If
Use Asc within your data-validation routines to determine such conditions as whether the first character is upper- or lowercase and whether it is alphabetic or numeric, as the following example demonstrates:
Private Sub Button1_Click(ByVal sender As System.Object, ...