Make the first character of a string lowercase

Lowercase only the first character.

JavaScript Version 1.0.0 · MIT · .md

function lowercaseFirst(text) { return `${text.charAt(0).toLowerCase()}${text.slice(1)}`; }

Input & expected output

"Delivered"

"delivered"

The edge case

""

""

Know the limits

• charAt works on UTF-16 code units; for text that may start with an emoji, use the code-point version in Decapitalize a string.

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.