Reverse the order of lines of a text

Split on LF or CRLF and reverse the lines.

JavaScript Version 1.0.0 · MIT · .md

function reverseLines(text) { return text.split(/\r?\n/).reverse().join('\n'); }

Input & expected output

"one\ntwo\nthree"

"three\ntwo\none"

The edge case

""

""

Know the limits

• Line endings become LF.

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.