04-prototypal-inheritance.js

/**
 * ******************************
 * Prototypal Inheritance
 * ******************************
 **/

/**
 * ********************
 * Person constructor & prototype
 * ********************
 **/

// Person constructor
function Person(firstName, lastName) {
  this.firstName = firstName;
  this.lastName = lastName;
}

// Greeting prototype
Person.prototype.greeting = function() {
  return `Hello there ${this.firstName} ${this.lastName}`;
};

const person1 = new Person('John', 'Doe');
console.log(person1.greeting());

/**
 * ********************
 * Customer constructor & prototype
 * ********************
 **/

// Customer constructor
function Customer(firstName, lastName, phone, membership) {
  Person.call(this, firstName, lastName);
  this.phone = phone;
  this.membership = membership;
}

// Inherit the Person prototype methods
Customer.prototype = Object.create(Person.prototype);
// Make customer.prototype return Customer()
Customer.prototype.constructor = Customer;

// Create customer
const customer1 = new Customer('Tom', 'Smith', '555-555-5555', 'Standard');
console.log(customer1);
console.log(customer1.greeting()); // Person Greeting Prototype

/**
 * ********************
 * Overriding inheritance prototype
 * ********************
 **/

// Customer greeting
Customer.prototype.greeting = function() {
  return `Hello there ${this.firstName} ${this.lastName} welcome to our company`;
};

console.log(customer1.greeting()); // Override Person Greeting with Customer Greeting Prototype.