# isString

**Kind:** Function

**Source:** [`packages/common/utils/shared.utils.ts`](https://github.com/nestjs/nest/blob/master/packages/common/utils/shared.utils.ts#L45)

**Part of:** [Common](subsystem-packages-common)

## Signature

```ts
function isString(val: any): val is string
```

## Parameters

| Name | Type |
|---|---|
| `val` | `any` |

**Returns:** `val is string`

## Used by

22 references from 22 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

### Imported by (22)

- `RouteDefinition` — `packages/core/router/paths-explorer.ts`:17
- `ParamProperties` — `packages/core/router/router-execution-context.ts`:50
- `flattenRoutePaths` — `packages/core/router/utils/flatten-route-paths.util.ts`:5
- `modulesContainer` — `packages/core/middleware/routes-mapper.ts`:148
- `anonymousMiddleware` — `packages/core/middleware/utils.ts`:77
- `InjectorDependency` — `packages/core/injector/injector.ts`:51
- `INSTANCE_METADATA_SYMBOL` — `packages/core/injector/instance-wrapper.ts`:22
- `Module` — `packages/core/injector/module.ts`:44

…and 14 more.