Convert snake case to camel case

Uppercase a lowercase ASCII letter immediately after an underscore.

JavaScript Version 1.0.0 · MIT · .md

function camelCase(value) { return value.replace(/_([a-z])/g, (_, letter) => letter.toUpperCase()); }

Input & expected output

"idempotency_key"

"idempotencyKey"

The edge case

"alreadyCamel"

"alreadyCamel"

Know the limits

• Consecutive underscores, digits and uppercase letters are preserved unless directly matched.
• Use this for a known naming convention, not arbitrary human text.

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.
• Check a palindrome — Compare a string with its code-point reversal.