Update CaesarCipher.swift

5-arrays-and-sets/caesar-cipher/CaesarCipher.swift

@@ -1,25 +1,36 @@
 // Caesar Cipher 🏛
-// Sonny Li
+// Patrick Jakobsen
 
-var alphabet: [Character] = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"]
-
-var secretMessage = "Codecademy".lowercased()
-
-var message = Array(secretMessage)
-
-for i in 0 ..< message.count {
-
-  for j in 0 ..< alphabet.count {
+struct CaesarCipher {
 
-    if message[i] == alphabet[j] {
-
-      message[i] = alphabet[(j+3) % 26]
-      break
-
+    private let shift: Int
+
+    init(shift: Int = 3) {
+        self.shift = shift
     }
 
-  }
-
+    func encrypt(_ text: String) -> String {
+        let lowercaseText = text.lowercased()
+
+        return String(
+            lowercaseText.map { character in
+
+                guard let ascii = character.asciiValue else {
+                    return character
+                }
+
+                let shifted = ((Int(ascii) - 97 + shift) % 26) + 97
+
+                return Character(UnicodeScalar(shifted)!)
+            }
+        )
+    }
 }
 
-print(message)
+// Example
+
+let cipher = CaesarCipher()
+
+let encryptedMessage = cipher.encrypt("Codecademy")
+
+print(encryptedMessage) // frghfdghpb