需要帮助解析JSON响应Angular 4

Question

我在angular 4和PHP，Mysql上工作。我从服务器得到的响应是

[{"transportation_pf":"1"},[{"destination":"Swarget"}],
{"transportation_pf":"5"},[{"destination":"Swarget"},
{"destination":"Dombivli"}]]

总线服务和组件是

import { Injectable } from '@angular/core';
import {Bus } from './bus';
import {Headers,Http } from '@angular/http';
import {Observable} from'rxjs/Observable';
import 'rxjs/add/operator/toPromise';

@Injectable()
export class BusService {
private busUrl='http://localhost/MycityDB/bus.php';
constructor(private http:Http) { }

getPlatforms(){

return this.http.get(this.busUrl).map(
(res)=>res.json()   
);

}

private handleError(error: any): Promise<any> {
console.error('An error occurred', error);
return Promise.reject(error.message || error);
}

}

总线组件是

import { Component, OnInit } from '@angular/core';
import { Bus } from './bus';
import {BusService } from './bus.service';
import { Http } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/forkJoin';
import 'rxjs/add/operator/map';


@Component({
selector: 'app-bus',
templateUrl: './bus.component.html',
styleUrls: ['./bus.component.css']
})
export class BusComponent implements OnInit {

busData: Bus[];
loadedCharacter: {};
private busUrl='http://localhost/MycityDB/bus.php';
constructor(private http: Http,private busservice: BusService) { }

ngOnInit() {
this.busservice.getPlatforms().subscribe(
(data)=>this.busData=data    
);

}

}

总线组件html是

<p *ngFor="let bus of busData">
Bus works ! {{bus.destination}}
</p>

总线类，如下所示

export class Bus {
transportation_pf : string;
destination: string[];
}

Html输出只显示代码出错的地方。

# Bus works ! #
# Bus works ! #
# Bus works ! #
# Bus works ! #

有人能帮上忙吗？我很困惑。