# merge

**将多个 `Observables` 合并成一个**

![](/files/-MWlwPzV78oQ3MHBEcr1)

通过使用 **merge** 操作符你可以将多个 `Observables` 合并成一个，当某一个 `Observable` 发出一个元素时，他就将这个元素发出。

如果，某一个 `Observable` 发出一个 `onError` 事件，那么被合并的 `Observable` 也会将它发出，并且立即终止序列。

## 演示

```swift
let disposeBag = DisposeBag()

let subject1 = PublishSubject<String>()
let subject2 = PublishSubject<String>()

Observable.of(subject1, subject2)
    .merge()
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

subject1.onNext("🅰️")

subject1.onNext("🅱️")

subject2.onNext("①")

subject2.onNext("②")

subject1.onNext("🆎")

subject2.onNext("③")
```

**输出结果：**

```swift
🅰️
🅱️
①
②
🆎
③
```


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