工厂方式，缺点：永远指向obj ```js function Person(name, age, work){ let obj=new Object(); obj.name=name; obj.age=age; obj.work=work;
return obj; }
let a=new Person(‘ming’, 18, ‘teacher’); let b=new Person(‘ming’, 18, ‘teacher’);
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2. 构造函数 指向是对的（this），
缺点是里面的函数是会在内存被重复创建，浪费内存和性能
```js
function Person(name, age, work){
this.name=name;
this.work=work;
this.age=age;
this.showName=function(){
console.log(this.name);
}
}
let a=new Person('ming', 18, 'teacher');
let b=new Person('ming', 18, 'teacher');
2.1 解决内存浪费问题，把复用的函数放到原型上。
function Person(name, age, work){
this.name=name;
this.work=work;
this.age=age;
}
Person.prototype.showName = function(){
console.log(this.name);
}
let a=new Person('ming', 18, 'teacher');
let b=new Person('ming', 18, 'teacher');
a.showName()