freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting/boo-who.md

---
id: a77dbc43c33f39daa4429b4f
title: Boo who
challengeType: 5
forumTopicId: 16000
dashedName: boo-who
---

# --description--

Check if a value is classified as a boolean primitive. Return true or false.

Boolean primitives are true and false.

# --hints--

`booWho(true)` should return true.

```js
assert.strictEqual(booWho(true), true);
```

`booWho(false)` should return true.

```js
assert.strictEqual(booWho(false), true);
```

`booWho([1, 2, 3])` should return false.

```js
assert.strictEqual(booWho([1, 2, 3]), false);
```

`booWho([].slice)` should return false.

```js
assert.strictEqual(booWho([].slice), false);
```

`booWho({ "a": 1 })` should return false.

```js
assert.strictEqual(booWho({ a: 1 }), false);
```

`booWho(1)` should return false.

```js
assert.strictEqual(booWho(1), false);
```

`booWho(NaN)` should return false.

```js
assert.strictEqual(booWho(NaN), false);
```

`booWho("a")` should return false.

```js
assert.strictEqual(booWho('a'), false);
```

`booWho("true")` should return false.

```js
assert.strictEqual(booWho('true'), false);
```

`booWho("false")` should return false.

```js
assert.strictEqual(booWho('false'), false);
```

# --seed--

## --seed-contents--

```js
function booWho(bool) {
  return bool;
}

booWho(null);
```

# --solutions--

```js
function booWho(bool) {
  return typeof bool === "boolean";
}

booWho(null);
```