SOURCE

function create(subObj,parentObj){
    const newObj = Object.create(parentObj)
    subObj.prototype = newObj
    Object.defineProperty(subObj.prototype,'constructor',{
        configurable:false,
        enumerable:false,
        writable:true,
        value:subObj,
    })
}
function createObj1(subObj,parentObj){
    const a = {}
    Object.setPrototypeOf(a,parentObj.prototype)
    Object.defineProperty(a,'constructor',{
        configurable:false,
        enumerable:false,
        writable:true,
        value:subObj,
    })
    subObj.prototype = a
}
function createObj(subObj,parentObj){
    function a(){}
    a.prototype = parentObj.prototype
    const newObj = new a()
    Object.defineProperty(newObj,'constructor',{
        configurable:false,
        enumerable:false,
        value:subObj,
        writable:true,
    })
    return newObj
}

function Person(name,age){
	this.name = name
    this.age = age
}

Person.prototype.eating = () => {
    console.log("eating")
}

function Student(name,age,sno) {
    Person.call(this,name,age)
	this.sno = sno
}

//方式一
// create(Student,Person.prototype)
//方式二
// Student.prototype = createObj(Student,Person)
//方式三
createObj1(Student,Person)

Student.prototype.study = () => {
    console.log("study")
}

const stu = new Student("zhangsan",18,'0001')
console.log(stu.name,stu.age,stu.sno)
stu.eating()
console.log(stu)
//上面三个方法中的Object.defineProperty就是为了修改此处打印结果的
console.log(stu.constructor.name)