---
title: "CFRunLoopTimerIsValid(_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfrunlooptimerisvalid(_:)"
---

# CFRunLoopTimerIsValid(_:)

Returns a Boolean value that indicates whether a CFRunLoopTimer object is valid and able to fire.

## Declaration

```swift
func CFRunLoopTimerIsValid(_ timer: CFRunLoopTimer!) -> Bool
```

## Parameters

- `timer`: The run loop timer to examine.

## Return Value

Return Value true if timer is valid; otherwise false.

## Discussion

Discussion A non-repeating timer is automatically invalidated after it fires.

## See Also

### CFRunLoopTimer Miscellaneous Functions

- [CFRunLoopTimerCreateWithHandler(_:_:_:_:_:_:)](corefoundation/cfrunlooptimercreatewithhandler(_:_:_:_:_:_:).md)
- [CFRunLoopTimerCreate(_:_:_:_:_:_:_:)](corefoundation/cfrunlooptimercreate(_:_:_:_:_:_:_:).md)
- [CFRunLoopTimerDoesRepeat(_:)](corefoundation/cfrunlooptimerdoesrepeat(_:).md)
- [CFRunLoopTimerGetContext(_:_:)](corefoundation/cfrunlooptimergetcontext(_:_:).md)
- [CFRunLoopTimerGetInterval(_:)](corefoundation/cfrunlooptimergetinterval(_:).md)
- [CFRunLoopTimerGetNextFireDate(_:)](corefoundation/cfrunlooptimergetnextfiredate(_:).md)
- [CFRunLoopTimerGetOrder(_:)](corefoundation/cfrunlooptimergetorder(_:).md)
- [CFRunLoopTimerGetTypeID()](corefoundation/cfrunlooptimergettypeid().md)
- [CFRunLoopTimerInvalidate(_:)](corefoundation/cfrunlooptimerinvalidate(_:).md)
- [CFRunLoopTimerSetNextFireDate(_:_:)](corefoundation/cfrunlooptimersetnextfiredate(_:_:).md)