Convert a number to equivalent characters

Turn a zero-based index into a spreadsheet-style column name.

JavaScript Version 1.0.0 · MIT · .md

function toChars(n) { return `${n >= 26 ? toChars(Math.floor(n / 26) - 1) : ''}${'ABCDEFGHIJKLMNOPQRSTUVWXYZ'[n % 26]}`; }

Input & expected output

27

"AB"

The edge case

0

"A"

Know the limits

• Zero-based: 0 is A and 25 is Z. The inverse of Convert the name of an Excel column to a number, minus one.

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

• Clamp a number to a range — Keep a number inside an inclusive minimum and maximum.
• Round to a number of digits — Apply decimal scaling and JavaScript rounding for display-oriented values.
• Add an ordinal suffix to a number — Append st, nd, rd or th to a positive integer.