How do I use a static variable in ES6 class?

Question

I\'m trying to use a static variable in es6. I\'d like to declare a static variable count in Animal class and increase it. However, I couldn\'t declare

Answer 1

Static class-side properties and prototype data properties must be defined outside of the ClassBody declaration.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes

class Animal {

  static increaseCount() {
    Animal.count += 1;
  }

  static getCount() {
    return Animal.count;
  }
}

Animal.count = 0;

Animal.increaseCount();
console.log(Animal.getCount()); // undefined