对象的constructor属性, 最初是用来标识对象类型的. 比如 ,我们定义一个 Person类,然后实例化两个对象. function Person(name, age, job){this.name = name;this.age = age;this.job = job;this.sayName = function(){alert(this.name);};}var person1 = new Person(“Jam”, 25, “Software Engineer”);var pe…