<!DOCTYPE html>
<html>

    <head>
        <meta charset="UTF-8">
        <title></title>

        <script type="text/javascript">
            //构造器（有参构造器）
            function Student(name, age) {
                this.name = name;
                this.age = age;
                //如果有属性，不希望通过构造器给值
                this.grade = "";

                this.study = function() {
                    document.write(this.name + "才" + this.age + "岁，就那么的爱学习");
                }

                this.eat = function() {
                    document.write(this.name + "今年" + this.grade);
                }
            }
        </script>
    </head>
    <!--     
        描述：类 （推荐）
    -->

    <body>
        <script type="application/javascript">
            var student1 = new Student("小周同学", 18);
            var student2 = new Student("隔壁老王", 58);

            student1.study();
            student1.grade = "大四";
            student1.eat();

            student2.study();
        </script>
    </body>

</html>