js怎么建类啊，有人能看看吗

创建两个类，分别为人类和地球类，人类中有两个方法 是吃和喝，地球类中有两个方法 是食物和水，结合两者，输出内容：1.“人类在吃地球上的食物”2.“人类在喝地球上的水”

    <script type="text/javascript">
        var earth = function () {
            this.food = function () {
                return '地球上的食物';
            };
            this.water = function () {
                return '地球上的水';
            };
        };

        var human = function () {
            this.eat = function () {
                return '人类在吃';
            };
            this.drink = function () {
                return '人类在喝';
            };
        };

        var myEarth = new earth;
        var myHuman = new human;

        document.write('1.' + myHuman.eat() + '' + myEarth.food());
        document.write('<br/>');
        document.write('2.' + myHuman.drink() + '' + myEarth.water());
    </script>

public class Test {
    static class Earth {
        public String food(){
            return "地球上的食物";
        }
        public String water(){
            return "地球上的水";
        }
    }
    static class Human {
        private Earth earth;
        public Human(Earth earth) {
            this.earth = earth;
        }
        public String eat(){
            return "人类在吃" + earth.food();
        }
        public String drink(){
            return "人类在喝" + earth.water();
        }
    }

    public static void main(String[] args) {
        Earth earth = new Earth();
        Human human = new Human(earth);
        System.out.println(human.eat());
        System.out.println(human.drink());
    }
}

ES6 入门教程 https://es6.ruanyifeng.com/#docs/class

es6 Class了解一下。