June 2018 Update

Task/Caesar-cipher/VBA/caesar-cipher.vba

@@ -0,0 +1,34 @@
+Option Explicit
+
+Sub Main_Caesar()
+Dim ch As String
+    ch = Caesar_Cipher("CAESAR: Who is it in the press that calls on me? I hear a tongue, shriller than all the music, Cry 'Caesar!' Speak; Caesar is turn'd to hear.", 14)
+    Debug.Print ch
+    Debug.Print Caesar_Cipher(ch, -14)
+End Sub
+
+Function Caesar_Cipher(sText As String, lngNumber As Long) As String
+Dim Tbl, strGlob As String, strTemp As String, i As Long, bytAscii As Byte
+  Const MAJ As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    Const NB_LETTERS As Byte = 26
+      Const DIFFASCIIMAJ As Byte = 65 - NB_LETTERS
+        Const DIFFASCIIMIN As Byte = 97 - NB_LETTERS
+
+    strTemp = sText
+    If lngNumber < NB_LETTERS And lngNumber > NB_LETTERS * -1 Then
+        strGlob = String(NB_LETTERS * 4, " ")
+        LSet strGlob = MAJ & MAJ & MAJ
+        Tbl = Split(StrConv(strGlob, vbUnicode), Chr(0))
+        For i = 1 To Len(strTemp)
+            If Mid(strTemp, i, 1) Like "[a-zA-Z]" Then
+                bytAscii = Asc(Mid(strTemp, i, 1))
+                If Mid(strTemp, i, 1) = Tbl(bytAscii - DIFFASCIIMAJ) Then
+                    Mid(strTemp, i) = Tbl(bytAscii - DIFFASCIIMAJ + lngNumber)
+                Else
+                    Mid(strTemp, i) = LCase(Tbl(bytAscii - DIFFASCIIMIN + lngNumber))
+                End If
+            End If
+        Next i
+    End If
+    Caesar_Cipher = strTemp
+End Function