greeting_es+.js

class Greeting {

    static intro = 'Hello ';

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

    get hello() {
        return Greeting.intro + this.name;
    }

}

const greeting = new Greeting('Charlie');

console.log(greeting.hello);

Greeting_ES6.js

class Greeting {

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

    get hello() {
        return Greeting.intro + this.name;
    }

}

Greeting.intro = 'Hello ';
const greeting = new Greeting('Charlie');

console.log(greeting.hello);

Greetings_ES2015.js

'use strict';

var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

var Greeting = function () {
    function Greeting(name) {
        _classCallCheck(this, Greeting);

        this.name = name;
    }

    _createClass(Greeting, [{
        key: 'hello',
        get: function get() {
            return Greeting.intro + this.name;
        }
    }]);

    return Greeting;
}();

Greeting.intro = 'Hello ';


var greeting = new Greeting('Charlie');

console.log(greeting.hello);