Question

我目前正在学习RxJS，却没有。我有以下代码：

mapOfPeople = new Map<number, any>();

const people = [
  { name: 'Sue', age: 25 },
  { name: 'Joe', age: 30 },
  { name: 'Frank', age: 25 },
  { name: 'Sarah', age: 35 }
];

from(people)
  .pipe(
    groupBy(
      person => person.age,
      p => p
    ),
    mergeMap(group => zip(of(group.key), group.pipe(toArray())))
  )
  .subscribe(console.log);

这段代码来自教程。

我想将输出放入给定的哈希图中。我该如何处理？我不知道。

Answer 1

在这个相当人为的示例中，您只想在最后添加一个reduce运算符：

public class TestTabsBean implements Serializable {

   private String text;

   public String submit() {
      // cause page validation to fail
      return null;
   }

   public String getText() {
      return text;
   }

   public void setText(final String text) {
      this.text = text;
   }

}

Answer 2

mapOfPeople: any;

const people = [
  { name: 'Sue', age: 25 },
  { name: 'Joe', age: 30 },
  { name: 'Frank', age: 25 },
  { name: 'Sarah', age: 35 }
];

from(people)
  .pipe(
    groupBy(
      person => person.age,
      p => p
    ),
    mergeMap(group => zip(of(group.key), group.pipe(toArray())))
  )
  .subscribe(res => mapOfPeople = res /*or do whatever you want with the result*/);

有关更多信息：observable

Answer 3

我无法编译您的初始代码，并且在这种情况下我不确定zip部分是什么。

一种实现方法是使用订阅函数处理程序。目前它是console.log-但您可以在此处执行(arg) => void格式的任何操作（该函数从可观察对象中获取项目并以某种方式处理它。

下面是一个将各个年龄段的人添加到地图中的示例：

type Person = { name: string, age: number};

const mapOfPeople = new Map<number, Person[]>();

const people = [
  { name: 'Sue', age: 25 },
  { name: 'Joe', age: 30 },
  { name: 'Frank', age: 25 },
  { name: 'Sarah', age: 35 }
];

from(people).pipe(
  groupBy(person => person.age),
  mergeMap(group => group.pipe(toArray()))
).subscribe(people => {
  // the age of any in this group of people is the key
  const { age } = people[0];

  // set as map's value for this age
  mapOfPeople.set(age, people);
});

将MergeMap转换为Map RxJS打字稿

3 个答案: