Order Json object - json

Question

I'm creating a simple movie listing app with Angular 4. I'm making an HTTP GET request to fetch all the movies stored in a json file. They have some fields like "Id", "Title", "Genre", "Duration", etc. When i'm listing all the movies, how can i order them by ID descending, so that the last one appear first?
Here's the code that i am using to get this json data:
On my data service file:
getMovies(){
return this.http.get('assets/data/movies.json')
.map(res => res.json());
}
On my component.ts file:
export class MainComponent implements OnInit {
movies: Movies[];
username:string;
userimg:string;
constructor(private userService:UserService, private dataService:DataService) { }
ngOnInit() {
this.dataService.getMovies().subscribe((movies) =>{
this.movies = movies;
});
}
}
interface Movies {
id:number,
title:string,
year:number,
rating:number,
cover:string,
genre:string,
duration:string,
description:string,
favourite:number
}
On my component.html file:
<div *ngFor="let movie of movies" class="row row-movies">
<a [routerLink]="['/movies', {'id': movie.id}]">
<div class="col-md-9">
<h3> {{movie.title}}</h3>
<h4> {{movie.year}}</h4>
<h4> {{movie.rating}}</h4>
<p>{{movie.description}}</p>
<h5> {{movie.genre}}</h5>
<h5> {{movie.duration}}</h5>
</div>
<div class="col-md-3">
<img src="../assets/img/capas/movies/{{movie.capa}}" class="img-responsive capa-filme" width="350px" />
</div>
</a>
</div>
Can you help me please? I'm still very noob with Angular..

Answer 1

This question has nothing to do with angular. You need to do, after loading the movies, something like this:
this.movies.sort((a,b) => (b.id - a.id));
As a note: this works using any Array in vanilla javascript.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

Answer 2

If you don't need the sort to change, you can do it as you retrieve the data.
this.dataService.getMovies().subscribe((movies) =>{
movies.sort((a, b) => {
return a.id < b.id ? 1 : -1;
});
this.movies = movies;
});
NOTE: I did not syntax check this.