To get negativeTimestamp, why does it throw NaN error when 0 minus a positive number?

Asked Oct 19 '16 at 15:02

Active Oct 20 '16 at 01:35

Viewed 190 times

hero.ts

export class Hero {
  name: string;
  timestamp: number;
  negativeTimestamp: number;

  constructor() {
    this.name = '';
    this.timestamp = firebase.database['ServerValue']['TIMESTAMP'];
    this.negativeTimestamp = 0 - firebase.database['ServerValue']['TIMESTAMP'];
  }

}

It throws error when I create an object from this class using new Hero(); The error message is

EXCEPTION: Uncaught (in promise): Error: Firebase.push failed: first argument contains NaN in property 'heroes.zeNtSMyJGvdZkMcxXsdfwSsbmSBrv2.negativeTimestamp'

this.timestamp works. It generated a timestamp value in Firebase database. That is correct. But how to get a negativeTimestamp?

My objective is to make timestamp from positive value to negative timestamp value. It's for using firebase descending ordering purpose.

edited Oct 20 '16 at 01:35

adjuremods

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asked Oct 19 '16 at 15:02

Jek

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You're trying to perform a client-side calculation with a server-side timestamp. I don't think that will work. – Frank van Puffelen Oct 19 '16 at 15:24
1

See also http://stackoverflow.com/a/34719492/3731501 – Estus Flask Oct 19 '16 at 15:27
What can I do to make it work on client-side? – Jek Oct 19 '16 at 15:27
After seeing estus posted link, I understand it now. I got a little hack to get this working with Angular2. Thanks. – Jek Oct 19 '16 at 15:32

To get negativeTimestamp, why does it throw NaN error when 0 minus a positive number?

0 Answers0