Created: Solution for Caesar's Cipher

Author: arindal1

L-A/0013 Caesar's Cipher/CaesarsCipher.js

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+function caesarCipher(str, k) {
+  // Helper function to shift a single character by k positions
+  function shiftChar(char, k) {
+    const isUpperCase = /[A-Z]/.test(char);
+    const alphabetSize = 26;
+
+    const baseCharCode = isUpperCase ? 'A'.charCodeAt(0) : 'a'.charCodeAt(0);
+    const shiftedCharCode = ((char.charCodeAt(0) - baseCharCode + k) % alphabetSize + alphabetSize) % alphabetSize + baseCharCode;
+
+    return String.fromCharCode(shiftedCharCode);
+  }
+
+  let result = '';
+
+  for (let i = 0; i < str.length; i++) {
+    const char = str[i];
+
+    if (/[A-Za-z]/.test(char)) {
+      result += shiftChar(char, k);
+    } else {
+      result += char; // Non-alphabetic characters remain unchanged
+    }
+  }
+
+  return result;
+}
+
+// Examples
+console.log(caesarCipher("middle-Outz", 2)); // ➞ "okffng-Qwvb"
+console.log(caesarCipher("Always-Look-on-the-Bright-Side-of-Life", 5)); // ➞ "Fqbfdx-Qttp-ts-ymj-Gwnlmy-Xnij-tk-Qnkj"
+console.log(caesarCipher("A friend in need is a friend indeed", 20)); // ➞ "U zlcyhx ch hyyx cm u zlcyhx chxyyx"