<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    class Human {
      constructor(name, age, weight) {
        this.name = name;
        this.age = age;
        this.weight = weight;
      };
      eat() {
        this.weight++;
      };
      sleep = () => {
        this.age++;
      };
    }
    const man = new Human('kim', 10, 70);
    man.eat();
    man.sleep();
    console.log(man);
  </script>
</body>
</html>