Data commit

Task/IBAN/VBA/iban.vba

@@ -0,0 +1,80 @@
+Public nations As New Collection
+Private Sub init()
+    nations.Add 24, "AD"
+    nations.Add 21, "CH"
+    nations.Add 22, "GB"
+    nations.Add 24, "SA"
+    nations.Add 20, "XK"
+End Sub
+
+Private Function mod97(ByVal c As String) As Integer
+    Dim n As Long
+    n = Val(Mid(c, 1, 9))
+    c = Mid(c, 10, Len(c) - 9)
+    n = n Mod 97
+    Do While Len(c) > 6
+        n = Val(Str(n) & Mid(c, 1, 7))
+        n = n Mod 97
+        c = Mid(c, 8, Len(c) - 7)
+    Loop
+    n = Val(Str(n) & c)
+    mod97 = n Mod 97
+End Function
+
+Private Function iban(ByVal code As String) As Boolean
+'-- This routine does and should reject codes containing spaces etc.
+'-- Use iban_s() below for otherwise.
+    On Error GoTo 1
+    lengths = nations(Mid(code, 1, 2))
+    If Len(code) = lengths Then
+        code = code & Mid(code, 1, 4)
+        code = Mid(code, 5, lengths)
+        Dim c As String: c = ""
+        Dim ch As String
+        For i = 1 To lengths
+            ch = Mid(code, i, 1)
+            If ch >= "0" And ch <= "9" Then
+                c = c & ch
+            Else
+                If ch >= "A" And ch <= "Z" Then
+                    c = c & Str(Asc(ch) - 55)
+                Else
+                    iban = False
+                End If
+            End If
+        Next i
+        c = Replace(c, " ", "")
+        iban = mod97(c) = 1
+    End If
+    Exit Function
+1:
+    iban = False
+End Function
+
+Private Function iban_s(code As String) As Boolean
+'-- strips any embedded spaces and hyphens before validating.
+    code = Replace(code, " ", "")
+    code = Replace(code, "-", "")
+    iban_s = iban(code)
+End Function
+
+Private Sub test(code As String, expected As Boolean)
+    Dim valid As Boolean
+    valid = iban_s(code)
+    Dim state As String
+    If valid = expected Then
+        state = IIf(valid, "ok", "invalid (as expected)")
+    Else
+        state = IIf(valid, "OK!!", "INVALID!!") & " (NOT AS EXPECTED)"
+    End If
+    Debug.Print code, state
+End Sub
+
+Public Sub main()
+    init
+    test "GB82 WEST 1234 5698 7654 32", True
+    test "GB82 TEST 1234 5698 7654 32", False
+    test "GB81 WEST 1234 5698 7654 32", False
+    test "SA03 8000 0000 6080 1016 7519", True
+    test "CH93 0076 2011 6238 5295 7", True
+End Sub