检测对象类型的两种方式，constructor属性和instanceof

//本例是为了记录检测对象类型的两种方式，即constructor属性和instanceof操作符。详见《高三》P145
        function Person(name, age, job) {
            this.name = name;
            this.age = age;
            this.job = job;
            this.say = function () {
                alert("hi,i'm " + name + "!");
            }
        }

        var person1 = new Person("kitty", 18, "Student");
        var person2 = new Person("wede", 29, "SoftWare");

        //利用constructor属性检测对象类型
        alert(person1.constructor == Person);  //true
        alert(person2.constructor == Person);  //true

        //利用instanceof操作符检测对象类型
        alert(person1 instanceof Person);  //true
        alert(person2 instanceof Person);  //true

        /********************************************************************************/

        //利用instanceof操作符同样也能检测到继承自Object基类的所有类型，比如这样：
        alert(person1 instanceof Object); //true
        alert(person2 instanceof Object); //true
        //对比constructor属性，可以看出，constructor属性的值为对象的直接父级
        alert(person1.constructor == Object); //false
        alert(person2.constructor == Object); //false

        //本例是上面示例的补充，意在说明函数的重构
        //详见《高三》P147
        function Person(name, age, job) {
            this.name = name;
            this.age = age;
            this.job = job;
            this.say = say; //注意，这里将外部函数say的作用域指向了函数内部
        }

        function say() {
            alert("Hello，I'm "+this.name+"，"+this.age+" years old,i'm a "+this.job);
        }

        var person1 = new Person("kitty", 18, "Student");
        var person2 = new Person("wede", 29, "SoftWare");

        person1.say();
        person2.say();