Amb

在多個源 Observables 中， 取第一個發出元素或產生事件的 Observable，然後只發出它的元素

let subject1 = PublishSubject<Int>()
let subject2 = PublishSubject<Int>()
let subject3 = PublishSubject<Int>()

subject1
    .amb(subject2)
    .amb(subject3)
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

subject2.onNext
 
(1)
subject1.onNext(20)
subject2.onNext(2)
subject1.onNext(40)
subject3.onNext(0)
subject2.onNext(3)
subject1.onNext(60)
subject3.onNext(0)
subject3.onNext(0)

/*
1
2
3
*/

Contains

判定一個 Observable 是否發射一個特定的值

Observable.of("2", "30", "22", "5", "60", "1").subscribe(onNext: {
    print($0.contains
 
("22"))
}).disposed(by: disposeBag)

/*
false
false
true
false
false
false
*/

DefaultIfEmpty

如果 Observables 為空, 發出預設值

Observable.of().ifEmpty(default: 0)
        .subscribe(onNext: { print($0) })
        .disposed(by: disposeBag)

/*
0
*/

SkipUntil

跳過 Observable 中頭幾個元素，直到另一個 Observable 發出一個元素

let source = PublishSubject<Int>()
let notifier = PublishSubject<Int>()

source.skipUntil(notifier)
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

source.onNext(1)
source.onNext(2)
source.onNext(3)
source.onNext(4)
source.onNext(5)

//開始接收訊息
notifier.onNext(0)

source.onNext(6)
source.onNext(7)
source.onNext(8)

// 仍然接收訊息
notifier.onNext(0)

source.onNext(9)

/*
6
7
8
9
*/

SkipWhile

跳過 Observable 中頭幾個元素，直到元素的判定為否

let disposeBag = DisposeBag()

Observable.of(2, 3, 4, 5, 6)
    .skipWhile { $0 < 4 }
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)
    }
}

/*
4
5
6
*/

TakeUntil

忽略掉在第二個 Observable 產生事件後發出的那部分元素

let source = PublishSubject<String>()
let notifier = PublishSubject<String>()

source
    .takeUntil(notifier)
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

source.onNext("a")
source.onNext("b")
source.onNext("c")
source.onNext("d")

//停止接收訊息
notifier.onNext("z")

source.onNext("e")
source.onNext("f")
source.onNext("g")

/*
a
b
c
d
*/

TakeWhile

該方法依次判斷 Observable 序列的每一個值是否滿足給定的條件。 當第一個不滿足條件的值出現時，它便自動完成

let disposeBag = DisposeBag()

Observable.of(2, 3, 4, 5, 6)
    .takeWhile { $0 < 4 }
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

/*
2
3
*/