# constructor屬性 >[danger]constructor 判斷構造器的類型來得知創建的對象的類型， ***** ```javascript function Person(name) { this.name = name; } function Dog(name) { this.name = name; } var p = new Person("p"); var d = new Dog("d"); console.log(p.constructor);//打印得到Person函數對象 console.log(d.constructor);//打印得到Dog函數對象 if(p.constructor == Person){ console.log("是Person對象"); } if(d.constructor == Dog){ console.log("是Dog對象"); } ```