Trim the file extension from a file name

Remove the text from the last dot onward.

JavaScript Version 1.0.0 · MIT · .md

function trimExtension(name) { const dot = name.lastIndexOf('.'); return dot > 0 ? name.slice(0, dot) : name; }

Input & expected output

"invoice-8812.pdf"

"invoice-8812"

The edge case

".env"

".env"

Know the limits

• The original turned ".env" into an empty string; a leading dot is kept here.

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.