Listening for variable changes in JavaScript

Question

Is it possible to have an event in JS that fires when the value of a certain variable changes? JQuery is accepted.

Answer 1

This is an old thread but I stumbled onto second highest answer (custom listeners) while looking for a solution using Angular. While the solution works, angular has a better built in way to resolve this using @Output and event emitters. Going off of the example in custom listener answer:

ChildComponent.html

Increment

ChildComponent.ts

import {EventEmitter, Output } from '@angular/core';

@Output() myEmitter: EventEmitter = new EventEmitter();

private myValue: number = 0;

public increment(n: number){
  this.myValue += n;

  // Send a change event to the emitter
  this.myEmitter.emit(this.myValue);
}

ParentComponent.html

{{n}}

ParentComponent.ts

public n: number = 0;

public monitorChanges(n: number){
  this.n = n;
  console.log(n);
}

This will now update non parent each time the child button is clicked. Working stackblitz