New Operator: ?.() conditional function call

[3xau1o]

Dart supports two conditional access mecanisms

Dart

foo?.bar // member
fooList?[1]  // subscript

There is a third conditional access mecanism for conditional functions calls, currently available on javascript from MDN

You can use optional chaining when attempting to call a method which may not exist. This can be helpful, for example, when using an API in which a method might be unavailable, either due to the age of the implementation or because of a feature which isn't available on the user's device.

Javascript

foo?.prop // member
fooList?.[expr] // subscript

// ↓↓↓↓
func?.(args) // function

[lrhn]

That was considered, actually as maybeFun?(args), when Dart introduced ?[...] for null aware indexing. It wasn't added, one reason being that it parses badly, another that maybeFun?.call(arga) is an adequate workaround.

Allowing a null-aware function call as maybeFun?.(args) is an option that has been considered as well. It's just that ?.call is still a perfectly adequate alternative, so it's never been urgent to shorten that. (And maybe we'd want the syntax for something else.)