Error in creating button on javafx

Question

https://code.sololearn.com/cL7aRikZ4lt5/?ref=app
I have error in
root.getChildren().add(btn)
error appears when I write .add (btn)

Answer 1

First call add for all nodes, after that call show. Not the other way round like you did.

Answer 2

Sorry, I'm on mobile and can't test your code.
Please add the stack trace error output.
I think, you have to call show at the end after you added all nodes, not at the beginning. But the error message might give a hint ;)

Answer 3

yes I know that I need show and scene I did it but error only in .add ()