HDBandit

String audioSystemVersion = "UNKNOWN";

if (myCar != null) {
    AudioSystem audioSystem = myCar.getAudioSystem();
    if (audioSystem != null) { // the card has audio system.
       audioSystemVersion = audioSystem.getVersion();
    }
}

HDBandit

Optional<AudioSystem> sc = Optional.empty(); 

HDBandit

AudioSystem audioSystem = new AudioSystem();
Optional<AudioSystem> as = Optional.of(audioSystem);

HDBandit

Optional<AudioSystem> as = Optional.ofNullable(audioSystem); 

HDBandit

AudioSystem as = ....;
if (as != null) {
   Sysmte.out.println(as);
}

HDBandit

Optional<AudioSystem> as = ...;
as.ifPresent(System.out::println);

HDBandit

Optional<AudioSystem> audioSystem = ...;
if(audioSystem.isPresent()){
  System.out.println(audioSystem.get());
}

HDBandit

AudioSystem as = ...;
if(as != null && "Pionner".equals(as.getBrand())){
  System.out.println(as);
}

HDBandit

Optional<AudioSystem> maybeAudioSystem = ...;
maybeAudioSystem.filter(as -> "Pionner".equals(as.getBrand())
                    .ifPresent(as -> System.out.println(as));

HDBandit

if(car != null){
  AudioSystem as = car.getAudioSystem();
  if(as != null && "Pionner".equals(as.getBrand()){
    System.out.println("ok");
  }
}