--- 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); ```