Update and rename AtBash.js to Atbash.js

Author: aryabharat

Ciphers/AtBash.js

@@ -0,0 +1,34 @@
+/*
+The Atbash cipher is a particular type of monoalphabetic cipher 
+formed by taking the alphabet and mapping it to its reverse, 
+so that the first letter becomes the last letter, 
+the second letter becomes the second to last letter, and so on. 
+*/
+
+
+/**
+ * Decrypt a Atbash cipher
+ * @param {String} str - string to be decrypted/encrypt
+ * @return {String} decrypted/encrypted string
+ */
+
+const Atbash = (message) => {
+    let decodedString = ''
+
+    for (let i = 0; i < message.length; i++) {
+        if (/[^a-zA-Z]/.test(message[i])) {
+            decodedString += message[i]
+        } else if (message[i] === message[i].toUpperCase()) {
+            decodedString += String.fromCharCode(90 + 65 - message.charCodeAt(i))
+        } else {
+            decodedString += String.fromCharCode(122 + 97 - message.charCodeAt(i))
+        }
+    }
+    return decodedString
+}
+
+// Atbash Example
+const encryptedString = 'HELLO WORLD'
+const decryptedString = Atbash(encryptedString)
+
+console.log(decryptedString) // SVOOL DLIOW