typescript - subscribe is not a function error thrown when trying to use JSON file in Angular 2 -

i'm trying import json file service , receiving error

error: uncaught (in promise): typeerror: this._qs.getbasicinfo(...).subscribe not function(…)

as of right service file looks

@injectable()  export class questionservice {  basicinfodata: observable<any>;  constructor(private http: http){}  getbasicinfo() {     this.basicinfodata = this.http.get('app/questionnaire/questions.json').map(res =>     res.json()).subscribe(data => this.basicinfodata = data ) observable<any>      return this.basicinfodata;     }  } 

and component looks this

@component({      moduleid    : module.id,     selector    : 'questionnaire-page',     templateurl : './questionnaire.component.html',     providers   : [ questionservice ] })  export class questionnairepage implements oninit, onchanges {      basicinfo: observable<any>;      constructor(private _qs: questionservice, private fbuild: formbuilder) {}      ngoninit() {         this._qs.getbasicinfo().subscribe( data => this.basicinfo = data );      console.log(this.basicinfo);     }  } 

prior trying call data service had working fine calling directly ngoninit() of component this

this.http.get('app/questionnaire/questions.json').subscribe(res => {      this.questions = res.json()      console.log(this.questions); }); 

i started out trying use same thing , read, added observable. came across post rxjs saying problem subscribing directly data before got there , fix use .map() first subscribe that. changed error undefined error 1 i'm getting figured step in right direction. i've been , forth trying sorts of things , either creates error indicating breaks before point or same error same snip of code. why happening?

this code returns subscription

getbasicinfo() {     this.basicinfodata = this.http.get('app/questionnaire/questions.json').map(res =>     res.json()).subscribe(data => this.basicinfo = data ) observable<any>      return this.basicinfodata;     } } 

subscribe method of observable not of subscription. want probably

getbasicinfo() {     return this.http.get('app/questionnaire/questions.json')     .map(res => res.json()); } 

this way observable returned can subscribed to.