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();