Wrap a number between two values

Map a number into [min, max) like an angle or a carousel index.

JavaScript Version 1.0.0 · MIT · .md

function wrap({ num, min, max }) { return ((((num - min) % (max - min)) + (max - min)) % (max - min)) + min; }

Input & expected output

{
  "num": 11,
  "min": 0,
  "max": 10
}

1

The edge case

{
  "num": -1,
  "min": 0,
  "max": 10
}

9

Know the limits

• max is exclusive. The lab requires min < max.

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.