On rare occasions, you may find yourself having to pass an Observable to another API that converts it into a proprietary type. This can be done simply by passing an Observable as an argument to a factory that does this conversion. However, this does not always feel fluent, and this is where the to() operator comes in.
For example, JavaFX has a Binding<T> type that houses a mutable value of type T, and it will notify affected user interface elements to update when it changes. RxJavaFX has JavaFxObserver.toBinding() and JavaFxSubscriber.toBinding() factories, which can turn an Observable<T> or Flowable<T> into a JavaFX Binding<T>. Here is a simple JavaFX Application that uses Binding<String> built-off Observable<String>, which is used to bind to a textProperty() operator of label:
import io.reactivex.Observable...