Sorting different objects into a combined list in Typescript-CodePudding

I have 2 arrays of different objects that I'd like to sort by date in my Angular application.

Object 1:

appointmentId: number, appointmentDate: Date

Object 2:

cancelId: number, cancelDate: Date

The following code sorts by the appointment date, how can I sort by the cancellation data at the same time so I have a combined sorted list?

let appointments = this.appointmentService.getAppointmentsForJob(this.jobId);
let cancellations = this.cancellationService.getCancellationsForJob(this.jobId);

forkJoin([appointments, cancellations]).subscribe(results => {
  this.appointments = results[0];
  this.cancellations = results[1];
  this.loading = false;
  this.combinedItems = ([]).concat(this.appointments, this.cancellations);
  this.combinedItems = this.combinedItems.sort((a, b) => a.appointmentDate - b.appointmentDate);
  console.log(this.combinedItems);

});

CodePudding user response：

You should know which property has a "higher" priority in sorting, i put it to be in the order that you gave. First appointmentDate, then cancelDate.

forkJoin([appointments, cancellations]).subscribe(results => {

  [this.appointments, this.cancellations] = results;

  this.loading = false;

  this.combinedItems = [...this.appointments, ...this.cancellations];

  const compareFn = (a: any, b: any) => {
      const compareByAppDate = a.appointmentDate - b.appointmentDate;
      const compareByCancelDate = a.cancelDate - b.cancelDate;
      return compareByAppDate || compareByCancelDate;
  }
   
  this.combinedItems = this.combinedItems.sort(compareFn)
  console.log(this.combinedItems);

});

CodePudding user response：

if you want to use both dates at the same time, you can change sort function like this:

this.combinedItems = this.combinedItems.sort((a, b) => {
  const dateA = a.appointmentDate || a.cancelDate;
  const dateB = b.appointmentDate || b.cancelDate;
  return dateA - dateB
});