Modeling with Nested Objects in TypeScript and Angular

ERROR: Unable to access 'applicants' property of undefined object

When my component initializes, I am attempting to execute the following code:

application: application;
ngOnInit(): void {
  this.application.applicants[0].type = "1";    <-- There seems to be an issue here
}

Below are the two classes that I have defined:

export class application{
  applicants: applicants[];
  constructor(applicants: applicants[]){this.applicants = applicants;}
}

export class applicants{
  type: String;
  constructor(type: String){this.type = type;}
}

Answer №1

Make sure to create an instance of the application class first before attempting to access any applicants. The constructor requires you to also create an array of applicants. See below for an example:

applicantsList: Applicant[] = [new Applicant("Applicant1"), new Applicant("Applicant2"), new Applicant("Applicant3")]
applicationInstance: Application = new Application(applicantsList)

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