JSFiddle - React, Tailwind, and code Playground

HTML

<div id="num">123</div>

Babel + JSX

class MyTest {
	constructor() {
    this.counter = document.getElementById('num');
  }
  
  setCount(count) {
  	return this.counter.innerHTML = count;
	};
  
	currentCount() {
  	return parseInt(this.counter.innerHTML);
	};
  
	incrementCount() {
  	return this.setCount(this.currentCount() + 1);
	};
  
	decrementCount() {
  	return this.setCount(this.currentCount() - 1);
	};
}

const test = new MyTest();

test.setCount(35);
test.incrementCount();
test.incrementCount();
test.incrementCount();