inheritance-class-a.js

class A {
  handleClick = () => {
    console.log("A.handleClick");
  }

  handleLongClick() {
    console.log("A.handleLongClick");
  }
}

console.log(A.prototype);
// {constructor: ƒ, handleLongClick: ƒ}

new A().handleClick();
// A.handleClick

new A().handleLongClick();
// A.handleLongClick