CODEWITHSUNDEEP
angularrxjs
yodalr
yodalr

Reputation: 10922

rxjs: Index and condition inside a map function

I have created an observable from a JSON array, I want to add new values for each element inside the array, and I need to do it based on the index of the element.

So far I'm only able to add same key-value for all the elements. Is there a way to introduce index into map function? So for example I can say that for the first element "is_leader" is true, and for all the others it's false.

Code so far:

this.dataSubscription = this.dataService.getTestData().subscribe(
  res => {
    this.allData = res.map(data => {
      data['is_leader'] = true;  // Here I would like a condition
      return data;
    });
  }
);

Working in Angular 2.

Upvotes: 0

Views: 7122

Answers (1)

jrelo
jrelo

Reputation: 238

Can you try this? 

this.dataSubscription = this.dataService.getTestData().subscribe(res => this.allData = res.map((data, index) => {
        data['is_leader'] = index === 0;
        return data;
    })
);

Upvotes: 5

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