Rxjs在数组中获取属性值的不同值 [英] Rxjs get distinct values of property value in array

问题描述

我正在尝试在可观察的数组中获取属性的不同值.

I am trying to get distinct values of a property in an observable array.

  let pt$ = Observable.of([{planTypeID : 1, description : 'test 1'}, 
                                {planTypeID : 2, description : 'test 2'}]);
    let planTypeIDs$ = pt$
        .flatMap(a => a)
        .map(a => a.planTypeID).distinct().toArray();

这是在rxjs中执行此操作的正确方法，还是有更好的方法?

Is this the right way to do it in rxjs, or is there a better way?

推荐答案

1. 您可以使用 .from 而不是 .of ，这样可以省去 .flatMap
2. distinct 默认情况下会检查引用，因此，如果您想比较内容，则应该创建某种哈希或创建自定义比较器-但这也许不是必需的.

1. You could use .from instead of .of, that should spare you the .flatMap
2. distinct will check the reference by default, so if you want to compare for contents you should create some kind of hash or make a custom comparer - but maybe that's not required here.

---

let pt$ = Observable.from([{planTypeID : 1, description : 'test 1'}, 
                            {planTypeID : 2, description : 'test 2'}]);
let planTypeIDs$ = pt$
    .map(a => a.planTypeID)
    .distinct()
    .toArray();

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