# #type?

## `#type?`

Private [string-type](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String) property of the type that causes an error to be thrown(or not thrown).

{% code title="type-error.class.ts" %}

```typescript
#type?: string;
```

{% endcode %}

### Type

#### [<mark style="color:green;">`string`</mark>](https://www.typescriptlang.org/docs/handbook/basic-types.html#string)