不能夠實例化angular2

Question

一類我有這樣

export class Policy { 
    constructor() { 
    } 
    emailAddress: string; 
    vehicleDetails: VehicleDetails[] 
} 

export class VehicleDetails { 
    constructor(policynumber: string, vinnumber: string) { 
     this.policyNumber = policynumber, 
      this.vinNumber = vinnumber 
    } 
    policyNumber: string; 
    vinNumber: string; 
} 

一類，現在我想要實例在這樣的組件的類，這是我綁定的形式值的提交方法。但是當我看到控制檯時，我得到一個未定義的錯誤。

var policy = new Policy(); 
    policy.emailAddress = formValue.controls.emailAddress._value; 
    formValue.controls.policyDetails.controls.forEach(function (x) { 
     policy.vehicleDetails.push(new VehicleDetails(x.controls.policyNumber._value, x.controls.vinNumber._value)); 
    }); 

爲什麼我沒有得到對象。

note：我還沒有提到@NgModule提供程序中的這兩個類。我@NgModule是這個

@NgModule({ 
    declarations: [ 
    LienholderComponent, 
    AppComponent, 
    PolicyVehicleComponent 
    ], 
    imports: [ 
    RouterModule.forRoot(
     APP_ROUTES, 
     { enableTracing: true } // <-- debugging purposes only 
    ), 
    BrowserModule, 
    FileUploadModule, 
    ReactiveFormsModule, 
    HttpModule 
    ], 
    bootstrap: [AppComponent] 
}) 
export class AppModule { } 

Answer 1

它可能是因爲你還沒有實例化的vehicleDetails陣列

應該是這樣的：「爲什麼我沒有得到的對象」

export class Policy { 
    constructor() { 
    } 
    emailAddress: string; 
    vehicleDetails: VehicleDetails[] = []; 
}