> For the complete documentation index, see [llms.txt](https://3440217568.gitbook.io/rxswift/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://3440217568.gitbook.io/rxswift/decision_tree/map.md).

# map

**通过一个转换函数，将 `Observable` 的每个元素转换一遍**

![](https://4217506537-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MWj545abP2yK86-qksJ%2Fsync%2F3bfb303488b2e340cc23a0ba888932e3629f007b.png?generation=1616819384586389\&alt=media)

**map** 操作符将源 `Observable` 的每个元素应用你提供的转换方法，然后返回含有转换结果的 `Observable`。

## 演示

```swift
let disposeBag = DisposeBag()
Observable.of(1, 2, 3)
    .map { $0 * 10 }
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)
```

**输出结果：**

```swift
10
20
30
```

## 参考

* [flatMap](/rxswift/decision_tree/flatmap.md)