es5设置属性不能修改

    /*es5*/
    {
        var Person ={
            name:'es5',
            age:19
        }

        Object.defineProperty(Person,'sex',{
            writable:false,
            value:'male'
        })

        console.table({
            name:person.get('name'),
            age:person.get('age')
        });

        Person.sex ='xxxx';

        console.table({
            name:person.get('name'),
            age:person.get('age')
        });
    }

效果图: