![JSON Object – { } Array – [ ] Separator – , : Var students = [ {name : “abc” , age : 20} , {name : “xyz” , age : 21} ];](https://image.slidesharecdn.com/oop-in-javascript4811/85/OOP-in-JavaScript-12-320.jpg)
OOP in JavaScript
- 1. OOP in JavaScript “ The World's Most Misunderstood Programming Language” Douglas Crockford
- 2. Some Myths JavaScript is related to Java JavaScript was developed by Sun Microsystems JavaScript is not Object Oriented JavaScript does not support data hiding, i.e. everything is public
- 3. OOP Concepts Encapsulation Inheritance Polymorphism
- 4. Encapsulation Definition Data + Operation Single logically organized unit Data visibility
- 5. Inheritance Definition Parent-child relationship between classes Child inherits Parents’ characteristics Child can redefine existing characteristics Child can add more characteristics
- 6. Polymorphism Definition Multiple functions Share a common name Context specific invocation The characteristic of being able to assign a different meaning or usage to something in different contexts ( http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci212803,00.html )
- 7. Encapsulation Private variables - Can only be accessed by private functions and privileged methods Private functions - Can only be called by privileged methods Privileged methods - May invoked by code external to the object Public properties - May be read/written from outside the object Public methods - Shared methods Prototype properties - Shared properties
- 8. Encapsulation function Student(name) { var age = 0; var checkAge = function(){ return (age > 0) ? age : false; }; this.getAge = function(){ return (checkAge()) ? age : “Age not set”; } this.setAge = function(_age){ age = _age; } this.name = name; this.constructor.prototype.updateTotal(); } Student.prototype.total = 0; Student.prototype.updateTotal = function(){ this.constructor.prototype.total++; }
- 9. Inheritance See Listing 1 See Listing 2
- 10. Polymorphism See Listing 1
- 11. What more? JSON Closures
- 12. JSON Object – { } Array – [ ] Separator – , : Var students = [ {name : “abc” , age : 20} , {name : “xyz” , age : 21} ];
- 13. References http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Reference http://mckoss.com/jscript/object.htm http://www.sitepoint.com/article/oriented-programming-1 http://www.codeproject.com/aspnet/JsOOP1.asp http://phrogz.net/JS/Classes/OOPinJS.html http://javascript.crockford.com/javascript.html http://kevlindev.com/tutorials/javascript/inheritance/index.htm http://www.dustindiaz.com/javascript-private-public-privileged/ http://developer.yahoo.com/yui/theater/ http://www.dustindiaz.com/json-for-the-masses/ http:// www.json.org / Google + Wikipedia = Many Many more references