面向对象的JavaScript-003

// Since JavaScript doesn't exactly have sub-class objects, prototype is a useful workaround to make a “base class” object of certain functions that act as objects. For example:
var Person = function() {
this.canTalk = true;
};

Person.prototype.greet = function() {
if (this.canTalk) {
console.log('Hi, I am ' + this.name);
}
};

var Employee = function(name, title) {
Person.call(this);
this.name = name;
this.title = title;
};

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

Employee.prototype.greet = function() {
if (this.canTalk) {
console.log('Hi, I am ' + this.name + ', the ' + this.title);
}
};

var Customer = function(name) {
Person.call(this);
this.name = name;
};

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

var Mime = function(name) {
Person.call(this);
this.name = name;
this.canTalk = false;
};

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

var bob = new Employee('Bob', 'Builder');
var joe = new Customer('Joe');
var rg = new Employee('Red Green', 'Handyman');
var mike = new Customer('Mike');
var mime = new Mime('Mime');

bob.greet();
// Hi, I am Bob, the Builder

joe.greet();
// Hi, I am Joe

rg.greet();
// Hi, I am Red Green, the Handyman

mike.greet();
// Hi, I am Mike

mime.greet();