added function

[jayanth-caw]

---

Summary By CodeKnack

📝 OVERVIEW

• Main purpose: Refactor string reversal logic into a reusable function and update a test case for isPalindrome.
• Type of changes: Refactoring (extracting duplicated logic) and test case modification.

🛠️ TECHNICAL DETAILS

• Added reverseString function:
  • Implements string reversal via split('').reverse().join(''), extracting logic previously inline in isPalindrome.
  • Reduces duplication by centralizing reversal logic.
• Updated isPalindrome test case:
  • Changed input from 'madam' (a palindrome) to 'hello' (non-palindrome), altering the test output.
• No new dependencies or services introduced:
  • Pure JavaScript implementation; no external libraries or APIs involved.
• API changes:
  • isPalindrome now calls reverseString instead of directly using split('').reverse().join('').
• No database schema changes:
  • Purely client-side code modification.

🏗️ ARCHITECTURAL IMPACT

• Reduced coupling:
  • Separates string reversal logic from the palindrome check, improving modularity.
• New abstraction:
  • Introduces reverseString as a reusable utility function.
• Dependency impact:
  • isPalindrome now depends on reverseString, creating a minor dependency chain.

🚀 IMPLEMENTATION HIGHLIGHTS

• Algorithm:
  • reverseString uses split('') (O(n) time) to convert the string to an array, reverse() (O(n/2) swaps), and join('') (O(n)), resulting in O(n) time complexity.
• Performance considerations:
  • Memory usage increases slightly due to array creation for reversal, but negligible for typical input sizes.
• Security implications:
  • No input validation in reverseString; passing non-string values (e.g., null, numbers) could cause errors.
• Error handling:
  • No explicit error handling for invalid inputs (e.g., non-string arguments).
• Test case change:
  • The updated test case now verifies the function correctly returns false for non-palindromic inputs like 'hello'.

Sequence Diagram

sequenceDiagram
    participant Test
    participant isPalindrome
    participant reverseString

    Test->>isPalindrome: "hello"
    activate isPalindrome
    isPalindrome->>reverseString: string
    activate reverseString
    reverseString-->>isPalindrome: reversed string
    deactivate reverseString
    isPalindrome-->>Test: boolean result
    deactivate isPalindrome

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[codeknackai]

Review Details By CodeKnack

📜 Changes

File	Change Type	Changes	Summary
code.js	Modified	+5/-1	The file code.js was modified to add a new reverseString function that implements string reversal via split('').reverse().join(''), duplicating logic previously inline in isPalindrome, and updated the final isPalindrome test case to log isPalindrome('hello') instead of 'madam', altering the tested input.

📒 Reviewed Files

• code.js

🧾 Reviewed Commits

• 6071a85

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[codeknackai]

The reverseString function lacks input validation. It assumes str is a string but doesn't check its type, which could cause runtime errors if non-string values are passed (e.g., undefined or numbers).

SUGGESTION:

Add type validation for the input:

+ if (typeof str !== 'string') {
+   throw new Error('Input must be a string');
+ }
 return str.split('').reverse().join('');