JSFiddle - React, Tailwind, and code Playground

JavaScript

class SetIntervalTest {
  constructor() {
    this.someNumber = 1;
  }

  trigger() {
      setInterval(this.setIntervalCallback, 400);
  }

  setIntervalCallback() {
      console.log(this.someNumber);
  }
}

const interval = new SetIntervalTest();

interval.trigger();