```typescript
import { isBoolean } from "node:node__util.d.ts";
```
isBoolean(object: unknown): object is boolean
Deprecated
Since v4.0.0 - Use `typeof value === 'boolean'` instead.
Returns `true` if the given `object` is a `Boolean`. Otherwise, returns `false`.
```js
import util from 'node:util';
util.isBoolean(1);
// Returns: false
util.isBoolean(0);
// Returns: false
util.isBoolean(false);
// Returns: true
```