如何使用get从httpclient URL中推出数组中的数据？

Question

我仍然是编程的新手，如果问题可能很愚蠢，我深表歉意。

但是我想知道如何在数组中保存“ get（url）”数据。 此数据在数组中，我想执行数组的长度

一旦 检索数组的长度，我将制作一种随机值以显示随机面的方法

。

import { Observable, Subject, Subscription } from 'rxjs';
import { FaceSnap } from './../models/face-snap.model';
import { Injectable } from "@angular/core";
import { HttpClient } from '@angular/common/http';
@Injectable({
  providedIn: 'root' //on renregistre ce service à la racine de l'application
})

export class FaceSnapService {


  // newFaceSnap$ = new Observable<FaceSnap[]>();

  constructor(private http:HttpClient){

  }

getAllFaceSnaps(): Observable<FaceSnap[]>{
  // return this.faceSnaps;
  return this.http.get<FaceSnap[]>('http://localhost:3000/facesnaps');
}

getFaceSnapById(faceSnapId: number): Observable<FaceSnap>{
  // const faceSnap = this.faceSnaps.find(faceSnap => faceSnap.id===faceSnapId)
  return this.http.get<FaceSnap>(`http://localhost:3000/facesnaps/${faceSnapId}`);
}


showOneFaceSnap(){
  const faceTab = [];

  this.http.get<FaceSnap[]>('http://localhost:3000/facesnaps').subscribe(facesnaps=> 
  facesnaps.forEach(data=> faceTab.push(data)) );


  console.log("array ",faceTab, "array length ", faceTab.length );

}

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.7.5/angular.min.js"></script>

Answer 1

AS rsd 提到，数据可在订阅中可用

let faceTab = [];

this.http.get<FaceSnap[]>('http://localhost:3000/facesnaps').subscribe(data=> 
 {
   faceTab = data;
   console.log(faceTab);
 });