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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: 2 var Person = function() { 3 this.canTalk = true; 4 }; 5 6 Person.prototype.greet = function() { 7 if (this.canTalk) { 8 console.log('Hi, I am ' + this.name); 9 } 10 }; 11 12 var Employee = function(name, title) { 13 Person.call(this); 14 this.name = name; 15 this.title = title; 16 }; 17 18 Employee.prototype = Object.create(Person.prototype); 19 Employee.prototype.constructor = Employee; 20 21 Employee.prototype.greet = function() { 22 if (this.canTalk) { 23 console.log('Hi, I am ' + this.name + ', the ' + this.title); 24 } 25 }; 26 27 var Customer = function(name) { 28 Person.call(this); 29 this.name = name; 30 }; 31 32 Customer.prototype = Object.create(Person.prototype); 33 Customer.prototype.constructor = Customer; 34 35 var Mime = function(name) { 36 Person.call(this); 37 this.name = name; 38 this.canTalk = false; 39 }; 40 41 Mime.prototype = Object.create(Person.prototype); 42 Mime.prototype.constructor = Mime; 43 44 var bob = new Employee('Bob', 'Builder'); 45 var joe = new Customer('Joe'); 46 var rg = new Employee('Red Green', 'Handyman'); 47 var mike = new Customer('Mike'); 48 var mime = new Mime('Mime'); 49 50 bob.greet(); 51 // Hi, I am Bob, the Builder 52 53 joe.greet(); 54 // Hi, I am Joe 55 56 rg.greet(); 57 // Hi, I am Red Green, the Handyman 58 59 mike.greet(); 60 // Hi, I am Mike 61 62 mime.greet();
