OOP is not about building applications.
You missed the point from the examples that you pointed out.

The point behind OOP is having highly extendable code.
Along with organization of code, usually more optimized, and a lot easier to make an application modular.

I'm sure you if look at those examples you will see that they are extending the classes.
If done properly it also gets rid of things like globals, and repetitive coding.

It's not just about classes either, there is quite a bit more to it.
Interfaces, Namespaces, objects themselves, all of the extra keywords that come with OOP and PHP 5.
There is a whole section on it in the PHP manual
PHP: Classes and Objects - Manual

This site has tutorials and a video series.
http://www.killerphp.com/tutorials/object-oriented-php/

Sounds like you're over thinking things and creating more work for yourself. Now go MVC and start using CodeIgniter. That little framework has made me so much money and saved me so much time.

Phpbbexpert - Thanks for the reference and clearing another concept of mine. I have already read that tutorial . I have all the basic and fundamental concepts.


ADAM - If you can further tell me more about PHP frameworks that what exactly they are ?? I have also read much about Zend framework and the last one you have define. Would u like to explain it further ??

The one big thing i find very useful about OOP as opposed to procedural is that you can clean up your function names.

if you were writing something without OOP you would need to make sure your function names don't clash.

in something like drupal where it is not OOP you have to make an effort to make sure your functions aren't named the same as someone elses functions.

They handle it by prefixing all the functions your module creates with the name of the module.

so if you created a module "Blue_balloons" then all of your functions would look like this:
so you know that your function names are unique. If this was OOP, you could shorten those names and not worry about clashes.
$balloon = new blue_balloons

then your function names look like this:
It makes things easier to read.

This book right here is IMO the best book available on learning OOP using PHP, I recommend it.

PHP Object Oriented Solutions

It's good that you want to learn more about OOP. This will definitely open many doors for you. For one it will make you more useful professionally. For another, it will make learning other programming languages easier. PHP was the first language that I learned OOP on an advanced level. After this experience, I found that it was quite easy to understand the concept of Java and Python, which both implement classes in a similar manner.

I think, once you study it, you'll find that the core concepts are not really very difficult. It's more just a set concepts that are very useful for managing larger systems, so don't be confused by the verbose terminology such as encapsulation, polymorphism, inheritance.

Encapsulation simply means that objects (instances of classes) can have their own private variables (fields) and functions (methods) in which to operate, without interfering with the properties of other objects or classes.

Polymorphism simply means that objects can take on many forms even though they are derived from the same class. This isn't really a feature, more just something that happens, depending on how classes are built and what their resulting objects are used for.

Inheritance is very important, because it allows the programmer to implement new classes from existing classes, by extending them. When a class is extended, in inherits some or all of the former classes properties, and might overwrite some of the properties. This is a very useful way of creating new classes without needing to rewrite the old ones. Also, you can extend pre-existing classes this way (such as the mysqli class, which comes packaged with PHP 5). In addition, some classes are not made to be instantiated (made into an object), but are only intended to be extended into other classes. This is known as an abstract class, which basically serves as a template for other classes.

Thanks all of you for helping me out. I know that there is no limit to learn. I don't think so that no body can be a complete programmer. Each time, we need someother one to get our hands completely on a new object. Thats why I am doing. In the last few days, I have create some small applications with the help of OOP. But, now I am little bit confuse.

Since, I have got that we can use classes to execute our MySQL queries. Doing some image resizing, creating categories tree. I have got that. I am creating a shopping cart and every thing is going in a right manner. The confusion here for me is that I am using now only OOP for each page. I have created a separate file to hold all the classes.
Infact, I am showing the HTML forms by using classes. No issue here. Only one thing is getting me into trouble that the classes.php file is becoming more heavy and heavy. Thats what, I am thinking about that Should I use classes only for executing MySQL queries or doing some other works like categories tree, image resizing etc..

Please clear this thing to me !!

Try autoloading your classes instead of putting them all into one file. The idea is to put each class in its own file, a file which has the same name as the class.

PHP: Autoloading Classes - Manual

Wayfarer - Thanks again for helping me out and telling me such an important thing about OOP. What I learnt is that not it can save only the time, but it can reduce your CPU usage as well. Autoload class function is such an awesome function by which we can get rid of rewriting the include and require statements again and again. Further, it only load that class which is really needed.



Usser - You may be telling exactly a rite thing, But then what it means to be an expert. We can simply use the already written code for various purposes. But, I never feel comfortable with this. Because I want to write each and every code with my hands

PHPbbexpert - You are absolutely write. Not only a single person, but a lot of person use that kind of codes which increase the security risk as well

I was not knowing that PHP is object oriented language.