Function ifUndefined

ifUndefined<TIn, TOut>(fn): ((value: TIn) => TOut | (TIn & ({} | null)))
Returns the output of fn if the input value is undefined. See also: ifNotUndefined and cancelIfUndefined.
Type Parameters
- TIn
- TOut
Parameters
- fn: (() => TOut)
  - - (): TOut
    - Returns TOut
Returns ((value: TIn) => TOut | (TIn & ({} | null)))
- - (value): TOut | (TIn & ({} | null))
  - Parameters
    - value: TIn
    Returns TOut | (TIn & ({} | null))