用js原型模式创建一个对象，编写三段代码

代码1：创建一个名为Person的构造函数，包含name和age属性和一个greet方法。

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

Person.prototype.greet = function() {
  console.log(`Hello, my name is ${this.name} and I am ${this.age} years old.`);
};

代码2：创建一个名为Student的构造函数，它继承自Person，包含一个major属性和一个study方法。

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

Student.prototype = Object.create(Person.prototype);
Student.prototype.constructor = Student;

Student.prototype.study = function() {
  console.log(`I am studying ${this.major}.`);
};

代码3：创建一个Person和Student对象并调用它们的方法。

const person = new Person('John', 30);
person.greet(); // 输出：Hello, my name is John and I am 30 years old.

const student = new Student('Jane', 20, 'Computer Science');
student.greet(); // 输出：Hello, my name is Jane and I am 20 years old.
student.study(); // 输出：I am studying Computer Science.