[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Object](https://evolu.dev/docs/api-reference/common/Object) › isFunction

```ts
function isFunction(value: unknown): value is Function;
```

Defined in: [packages/common/src/Object.ts:111](https://github.com/evoluhq/evolu/blob/dd96d79f1dbe9a49fa12ce8e0aa7d3d0177795ca/packages/common/src/Object.ts#L111)

Checks if a value is a function.

### Example

```ts

assertTrue(isFunction(() => {}));
assertTrue(isFunction(function () {}));
assertFalse(isFunction({}));
```