Class getters and setters

Previously getters and setters existed in ES5, you would've used Object.defineProperty to set them...

var player = {
    level: 5
};

Object.defineProperty(player, 'health', {
    get: function() {
        return player.level * 10.5;
    }
});

console.log(player.health); // 52.5

class Person {

    constructor(name) {
        this._name = name;
    }

    get name() {
        return this._name;
    }

    set name(name) {
        this._name = name;
    }

}

var person = new Person('Don');
person.name; //Don
person.name = 'Paul';
person.name; //Paul

Get and set allow us to use a bit of short hand to set variables and retrieve variables on the class.