javascript - Why and how to use Angular2/Typescript model? -

this first post , ask on topic can't seem find info of.

i've been learning angular 2 trough guide , ng-book creating "spotifyapp", , came across best practice create typescript class model of artist , album, import component , set result of http request model.

now don't see difference regular array, don't know why it, , can't seem find relevant info topic. works can't see does. tried break in example below giving random attributes, , no difference

i went angular official docs, , didn't see difference, gone trough typescript tutorial on tutorials point , doesn't mention it. question why need model, use wrong? , use in application?

artist.model.ts

   import { album } './album.model' export class artist{   id: number;   name: number;   peackock: string;   genres: any;   albums: album[]; } 

album.model.ts

export  class album {   id: number; } 

spotify-app.service

@injectable() export class spotifyappservice {    constructor(private http: http) {   }    searchbytrack(query: string) {     let params: string = [       `q=${query}`,       `type=artist`     ].join("&");      let queryurl = `https://api.spotify.com/v1/search?${params}`;     return this.http.get(queryurl).map(res => res.json());   }  } 

spotify-app.component.ts

export class spotifyappcomponent implements oninit {   searchstr: string;   artist: artist[];    constructor(private spotifyservice: spotifyappservice) { }    searchmusic(query: string):void{       this.spotifyservice.searchbytrack(query)        .subscribe( res => {        this.artist = res.artists.items;         });   };   ngoninit() {    }  } 

it's object. , have noticed can have other attributes , still work because forgiving. 1 obvious benefit code completion , error detection. open code in visual studio code , can control click definition.

edit: said gives code completion. ide know when start typing n keep going , fill in name. gives place attributes should expect. can add functions it. give more flexibility passed api.