Angular 将数组分配给另一个数组时出现未定义错误

Question

So in this component, i am getting an array of objects from the parent component, which i use to display a list of objects, but when i create a new array, and assign the first array to it and try to work with it, i get an error that the new array is undefined, here's my code:

export class AdherentsListComponent implements OnInit {
  // adherents: Adherent[];
  adherent: Adherent;

  @Input() adherents: Adherent[];

 
  constructor(private adherentService: AdherentService, private alertify: AlertifyService, private router: Router,private modalService: NgbModal) { }

  ngOnInit() {
  }
  
   tempAdherents = this.adherents; //this is what's not working

   loadAdherent(id){
    this.adherentService.getAdherent(id).subscribe((adherent: Adherent) => {
      this.adherent = adherent;
    }, error => {
      this.alertify.error(error);
    })
  }

}

Please any idea how can i create the new array, Thank you.

Answer 1

Try to initzialize your input like @Input() adherents: Adherent[] = [] as Adherent[];

Answer 2

You are missing a declaration for tempAdherents .

export class AdherentsListComponent implements OnInit {
  // adherents: Adherent[];
  adherent: Adherent;

  @Input() adherents: Adherent[];

 
  constructor(private adherentService: AdherentService, private alertify: AlertifyService, private router: Router,private modalService: NgbModal) { }

  ngOnInit() {
  }
  
   var tempAdherents = this.adherents; //this is what's not working

   loadAdherent(id){
    this.adherentService.getAdherent(id).subscribe((adherent: Adherent) => {
      this.adherent = adherent;
    }, error => {
      this.alertify.error(error);
    })
  }
}