---
title: "JSValueMakeUndefined(_:)"
framework: javascriptcore
role: symbol
role_heading: Function
path: "javascriptcore/jsvaluemakeundefined(_:)"
---

# JSValueMakeUndefined(_:)

Creates a JavaScript value of the undefined type.

## Declaration

```swift
func JSValueMakeUndefined(_ ctx: JSContextRef!) -> JSValueRef!
```

## Parameters

- `ctx`: The execution context to use.

## Return Value

Return Value The unique undefined value.

## See Also

### Creating Values

- [JSValueMakeNull(_:)](javascriptcore/jsvaluemakenull(_:).md)
- [JSValueMakeBoolean(_:_:)](javascriptcore/jsvaluemakeboolean(_:_:).md)
- [JSValueMakeNumber(_:_:)](javascriptcore/jsvaluemakenumber(_:_:).md)
- [JSValueMakeString(_:_:)](javascriptcore/jsvaluemakestring(_:_:).md)
- [JSValueMakeSymbol(_:_:)](javascriptcore/jsvaluemakesymbol(_:_:).md)