function Person(name,age){
this.name=name
this.age=age
}
Person.prototype.sayHi=function(){//原型是公共方法解决构造函数new对象公共属性和方法的内存浪费
console.log(this.name+' say hi!!')
}
const p1=new Person('aa',12)
const p2=new Person('bb',14)
p1.sayHi()
p2.sayHi()
console.log(p1.__proto__===Person.prototype) //true
console.log(p2.__proto__===Person.prototype)//true
console.log(p1.__proto__===p2.__proto__)//true
console.log(Person.prototype.constructor===Person)//true
console.log(Person.prototype.__proto__===Object.prototype) //true