Can you name the main types of operators and data types used in the RxJava library?

The main types of operators and data types in RxJava are:

• Observable — the primary type representing a data stream that can emit multiple items or errors.
• Single — a stream that emits exactly one item or an error.
• Maybe — can emit one item, nothing, or an error.
• Completable — does not emit items, only a completion or error signal.

Main types of operators:

• Creating operators: just(), fromIterable(), create(), interval() — create an Observable from various sources.
• Transforming operators: map(), flatMap(), filter(), scan() — transform or filter items.
• Combining operators: merge(), zip(), concat() — combine multiple Observables.
• Flow control: debounce(), throttle(), buffer() — control the speed and quantity of items.
• Error handling and retries: retry(), onErrorResumeNext() — handle errors.

Example of creating an Observable and applying the map operator:

Observable.just(1, 2, 3)
    .map(i -> i * 2)
    .subscribe(System.out::println); // Will output 2, 4, 6