25 JavaScript对象原型&ES5新的对象方法

<script>
     //对象构造器
     function Person(f,l,age,eyeColor){
         this.firstName = f;
         this.lastName = l;
         this.age = age;
         this.eyeColor = eyeColor;
         //为构造器添加属性和方法，必须在构造器函数里面添加，不能在外面添加(除非使用prototype)
         this.changeName = function(name){
             this.lastName = name;
         };
     }

     Person.prototype.nationality = "China";
     Person.prototype.changeAge = function(newAge){
         this.age = newAge;
     };
     var zhangsan = new Person("zhangsan","lisi",13,"blue");
     var liuliu = new Person("liuliu","qiqi",13,"blue");
     zhangsan.changeAge(100);
    //  document.getElementById("demo").innerHTML = zhangsan.nationality;
    document.getElementById("demo").innerHTML = zhangsan.age;
    </script>

<script>
        //ES5新的对象方法

        //添加或更改对象属性
        Object.defineProperty(obj, property, desc)

        //添加或更改多个对象属性
        Object.defineProperties(obj, descriptions)

        //访问属性
        Object.getOwnPropertyDescriptor(obj, property)

        //以数组形式返回所有属性
        Object.getOwnPropertyNames(obj)

        //以数组形式返回所有可枚举的属性
        Object.keys(obj)

        //访问原型
        Object.getPrototypeOf(obj)

        //组织向对象添加属性
        Object.preventExtensions(obj)

        //如果可将数学添加到对象，返回true
        Object.isExtensible(obj)

        //防止更改对象属性
        Object.seal(obj)

        //如果对象被密封，返回true
        Object.isSealed(obj)

        //防止对对象进行任何更改
        Object.freeze(obj)

        //如果对象被冻结，返回true
        Object.isFrozen(obj)
</script>