面向对象的JavaScript-003

1.

 // 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();