What is the default return value of a Dart function?

dart return

In Dart each function without an explicit return someValue; returns null;

The null object does not have a method 'call'.

makeAdder (add2) without return returns null and null(3) leads to the exception.

dart return

I would like to quote two important note here. It might help others:

Though Dart is Optionally typed ( meaning, specifying the return type of a function such as int or void is optional ), it always recommended to specify type wherever possible. In your code, as a sign of good programming practice, do mention the return type.
If your function does not return a value then specify void. If you omit the return type then it will by default return null.
All functions return a value. If no return value is specified, the statement return null; is implicitly appended to the function body.

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