---
title: kJSTypeUndefined
framework: javascriptcore
role: symbol
role_heading: Global Variable
path: javascriptcore/kjstypeundefined
---

# kJSTypeUndefined

The unique undefined value.

## Declaration

```swift
var kJSTypeUndefined: JSType { get }
```

## See Also

### Constants

- [kJSTypeNull](javascriptcore/kjstypenull.md)
- [kJSTypeBoolean](javascriptcore/kjstypeboolean.md)
- [kJSTypeNumber](javascriptcore/kjstypenumber.md)
- [kJSTypeString](javascriptcore/kjstypestring.md)
- [kJSTypeObject](javascriptcore/kjstypeobject.md)
- [kJSTypeSymbol](javascriptcore/kjstypesymbol.md)