distinctUntilChanged

distinctUntilChanged例子：

let disposeBag = DisposeBag()

Observable.of("🐱", "🐷", "🐱", "🐱", "🐱", "🐵", "🐱")
    .distinctUntilChanged()
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

输出结果

🐱
🐷
🐱
🐵
🐱