Classes-like functions example

function-classes.js

// class
function Foo(who){
  // constructor
  this.me = who;
  this.species = 'fufel';

  // methods
  Object.assign(Foo.prototype, {
    identify(){
      return 'I am ' + this.me;
    }
  });
}

// class
function Bar(who){ 
  // super(..)
  Foo.call(this, who);

  // extends
  Object.setPrototypeOf(
    Bar.prototype, Foo.prototype
  );

  // constructor
  this.subtype = 'barashek';
  
  // methods
  Object.assign(Bar.prototype, {
    speak(){
      console.log('Hello, ' + this.identify());
    }
  });
}

a1 = new Foo('a1');
b1 = new Bar('b1');
console.log(a1);
console.log(b1);