---
title: inRange
tags: math,beginner
firstSeen: 2017-12-20T18:33:58+02:00
lastUpdated: 2020-11-01T20:50:57+02:00
---

Checks if the given number falls within the given range.

- Use arithmetic comparison to check if the given number is in the specified range.
- If the second argument, `end`, is not specified, the range is considered to be from `0` to `start`.

```js
const inRange = (n, start, end = null) => {
  if (end && start > end) [end, start] = [start, end];
  return end == null ? n >= 0 && n < start : n >= start && n < end;
};
```

```js
inRange(3, 2, 5); // true
inRange(3, 4); // true
inRange(2, 3, 5); // false
inRange(3, 2); // false
```