javascript - 创建原型(prototype)链最安全、跨浏览器广泛支持的方法是什么？

Question

所以我仍在学习 JavaScript，并且现在正在使用原型(prototype)。我刚刚完成的类(class)向我展示了如何使用 __proto__ 来创建原型(prototype)继承链。这是我的意思的一个例子:

function Person(firstName,lastName,dob){
  this.firstName = firstName;
  this.lastName = lastName;
  this.dob = new Date(dob);
}
Person.prototype = {
  constructor: Person,
  getFullName: function(){
    return this.firstName + " " + this.lastName;
  },
  getAge: function(){
    var ageDiff = Date.now() - this.dob;
    var ageDiffDate = new Date(ageDiff);
    return Math.abs(ageDiffDate.getUTCFullYear() - 1970);
  }
}

function Employee(firstName,lastName,dob,position,dept){
  this.firstName = firstName;
  this.lastName = lastName;
  this.dob = new Date(dob);
  this.position = position;
  this.dept = dept;
  this.isFired = false;
}
Employee.prototype = {
  constructor: Employee,
  __proto__: Person.prototype,
  doWork: function(){
    console.log(this.getFullName() + " is doing work");
  }
}

function Manager(firstName,lastName,dob,dept){
  this.firstName = firstName;
  this.lastName = lastName;
  this.dob = new Date(dob);
  this.position = "Manager";
  this.dept = dept;
}
Manager.prototype = {
  constructor: Manager,
  __proto__: Employee.prototype,
  fireEmployee: function(emp){
    emp.isFired = true;
    console.log(this.getFullName() + " has fired " + emp.getFullName());
  }
}

var per = new Person("Bob","Saget","1990-02-05");
var emp = new Employee("Jane","Doe","1980-05-02","Clerk","Sales");
var mgr = new Manager("Jim","Smith","1970-09-10","Sales");

Employee 继承自 Person.prototype，Manager 继承自 Employee.prototype。漂亮又简单。

但是，我了解到 __proto__ 属性并不能在所有网络浏览器上得到保证，因为 ES6 尚未被广泛采用。我一直在浏览互联网，试图找到一个清晰的解释来说明该怎么做，但我有点迷失了。

除了使用 __proto__ 之外，在 ES5 中设置原型(prototype)继承链的安全且得到广泛支持的方法是什么？

Answer 1

最安全的方法是使用标准 ES5 及更高版本的方法。

function A() {}

function B() {}
B.prototype = Object.create(A.prototype);