Arrow Functions (Gosinta)

var solarsystem = {
    planets: ['Mercury', 'Venus', 'Earth', 'Mars', 'Jupiter', 
    'Saturn', 'Uranus', 'Neptune', 'Pluto (?)'],
    showPlanets: function() {
        this.planets.forEach(function(planet, idx) {
            console.log(this.planets[idx]);
        })
    }
};
solarsystem.showPlanets(); // crash! ⛔ 

var solarsystem = {
    planets: ['Mercury', 'Venus', 'Earth', 'Mars', 'Jupiter', 
    'Saturn', 'Uranus', 'Neptune', 'Pluto (?)'],
    showPlanets: function() {
        this.planets.forEach((planet, idx) => {
            console.log(this.planets[idx]);
        })
    }
};
solarsystem.showPlanets(); // success! 🌍