# checkOptionalParameter

**Kind:** Function

**Source:** [`src/utils/url.ts`](https://github.com/honojs/hono/blob/main/src/utils/url.ts#L171)

**Part of:** [Utils](subsystem-src-utils)

## Signature

```ts
function checkOptionalParameter(path: string): string[] | null
```

## Parameters

| Name | Type |
|---|---|
| `path` | `string` |

**Returns:** `string[] | null`

## Used by

3 references from 3 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

### Imported by (3)

- `LinearRouter` — `src/router/linear-router/router.ts`:11
- `RegExpRouter` — `src/router/reg-exp-router/router.ts`:47
- `TrieRouter` — `src/router/trie-router/router.ts`:5