withLatestFrom

withLatestFrom(second:)

let numberSubject = PublishSubject<Int>()
let emojiSubject = PublishSubject<String>()

print("\n---< withLatestFrom(second:) >---\n")
//파라미터로 넣은 emojiSubject의 마지막 이벤트가 호출하는 녀석인 numberSubject가 onNext 될 때마다 방출

numberSubject
  .withLatestFrom(emojiSubject)
  .subscribe(onNext: { print($0) })

emojiSubject.onNext("🐰")
emojiSubject.onNext("🙉")
emojiSubject.onNext("🐷")
emojiSubject.onNext("🐽")
emojiSubject.onNext("🐯")

numberSubject.onNext(1)
numberSubject.onNext(2)
numberSubject.onNext(3)
numberSubject.onNext(4)

🐯 🐯 🐯 🐯

withLatestFrom(second:, resultSelector: {})

print("\n---< numberSubject.withLatestFrom(second:, resultSelector: {}) >---\n")
//resultSelector를 추가해서 내가 원하는 대로 가공해서 방출

numberSubject
  .withLatestFrom(emojiSubject) { num, emoji in "\(num) \(emoji)" }
  .subscribe(onNext: { print($0) })

emojiSubject.onNext("🐰")
emojiSubject.onNext("🙉")
emojiSubject.onNext("🐷")
emojiSubject.onNext("🐽")
emojiSubject.onNext("🐯")

numberSubject.onNext(1)
numberSubject.onNext(2)
numberSubject.onNext(3)
numberSubject.onNext(4)

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