Check a palindrome

Compare a string with its code-point reversal.

JavaScript Version 1.0.0 · MIT · .md

function palindrome(value) { return value === Array.from(value).reverse().join(''); }

Input & expected output

"level"

true

The edge case

""

true

Know the limits

• Case, punctuation, spaces and Unicode normalization are significant.
• This is a literal comparison, not a language-aware word game.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Capitalize a string — Uppercase the first Unicode code point and preserve the remaining text.
• Reverse a string — Reverse Unicode code points without splitting surrogate pairs.
• Create a simple URL slug — Normalize a Latin-text label into lowercase ASCII words separated by hyphens.