angularjs - Angular2 Object Instantiation for Asynchronous Data -

i working on angular2 project gets object asynchronously api using new observable framework.

  this._accountsservice.getaccountdetails(this.id)     .subscribe(         accountdetails => this.accountdetails = accountdetails,         err => this.errormessage = <any>err,         () => console.log(this.accountdetails)   );       

when tried access property of object using interpolation {{accountdetails.username}} ,we got property undefined error, because object had not yet been received api. fixed instantiating object in class

 accountdetails: accountdetails = new accountdetails(); 

this works, noticed in angular 1, fake object created, if object undefined, there never an undefined error -- show empty value in interpolated code. change in angular2? also, noticed when used *ngfor in our code iterate through properties of object, display empty value (rather trigger object undefined error) if object had not yet been received api. occurs internally in *ngfor directive?

with first piece of code need following things,

1) because should {{accountdetails.username}} (not {{accountdetails.username}} ). note : please double check u or u can't tell without knowing object's properties.

2) use ?. {{accountdetails?.username}}

i hope help.