Angular, Typescript accessing nested model as array

trying to access the child member(is an array) of parent interface. But getting undefined.

export class Address {
    id: number;
    city: string;
    state: string;
}

import { Address } from './address';
export class User {
    id: number;
    name: string;
    alladdresses: Address[];
}

in my component - the declaration are

  users: User[] = [];
  address: Address[] = [];

and my http.get is

    selectUser(user: User) {
    let url = "http://localhost:8080/users/" + user.id
    this.http.get<User>(url).subscribe(

      res => {
        //console.log(res);
        this.selectedUser = res;
        console.log('selected user is:', this.selectedUser);

      },
      error => {
        console.log('error while getting user for ', user.id);
      },
      () => {
        console.log('complete');
      }
    );
  }

and the json response of user is

here the selected user I am displaying on the page, and some action on page calling another function to access the addresses - the array

createAddress() {
    let newAddress: Address = {
      id: null,
      city: "new city",
      state: "new state"
    }
    console.log(this.selectedUser)
    let address: Address[] = this.selectedUser.alladdresses
    //address.push(newAddress);
    console.log(address);
  }

But the array is undefined, not where waht going wrong.