Alright class - today I'm here to talk about the differences and similarities that PHP and Ruby have when it comes to object properties, methods, and their visibility - how you create variables inside classes, and how you can interact with them.

He compares the private properties in PHP classes to the corresponding handling in Ruby, including the getters and setters to go with them. There's also a look at class visibility settings in Ruby.

It has been a while, but here is part 4 of the PHP Quiz series! A few questions to crack your brain about, or perhaps you know them all? Try them and find out! Also do read the idea behind these quizzes, here: The PHP Quiz series

In this quiz he tests your knowledge of class visibility, fluent method handling, class extension, strptime and a tricky "for" loop. Take the quiz and see how you do.

In order to understand the purpose of encapsulation you first need to understand the purpose of classes. [...] In order for them to be used properly as they were designed, you will need to limit how users of the class can interact with those characteristics and functionality.

He looks at the visibility modifiers (public/private/protected), interface functions and some sample code showing how to use them in a simple class to work with a Person's set of data.

Out of the whole discussion, here is the points I got (aka understood) out of it. Please correct me in the comments if I'm off base in any way.

There's two points he makes in the remainder of the post:

• Methods should only be public when necessary.
• Private methods allow you to preserve the class' core functionality.

There's also a bit of code included to illustrate some of his points.

It's time to leap forward and tackle this final article of the series, which will be focused on covering some additional aspects concerning the use of this kind of class method. In addition, I'll teach you how to utilize the "final" keyword, which is included with PHP 5, to prevent the methods of a specific class from being overridden by any subclass.

They work from a hands-on example to show how they can work with private methods (expanding a bit from last time) and how to use the "final" keyword to restrict any and all modification for a method.

Now that you know what will be treated in this fourth chapter of the series, it's time to learn how to declare and implement public and protected methods with PHP 5 classes. Of course, as always I'm going to address this useful topic by using a hands-on approach, which means that there's a bunch of code samples ahead, waiting patiently for you.

They talk about calling methods globally first and then move into the keyword restrictions. They show the difference between a public method/variable and a protected one, including how to get at the protected members from a child class.

In the last article, I explained how to work with a couple of private properties that partially comprised the API of a basic class, which is useful for saving simple strings to a specified text file.

This part builds on this previous example but changes up the subclass (an instance of DataSaver) to use what they call an "accessor" - a function in the parent that returns the private variable/contstant's current value when called.

One of the most useful features that was introduced into the improved object model of PHP 5 is "member visibility." It provides PHP developers with the ability to specify the level of access each data member of a class will have in the context of a given application.

They review the other two keywords (public/protected) before venturing on to the use of "private" to protect, but allow access to, methods and properties in a parent class.

The previous concept can also be applied successfully when it comes to defining the visibility of properties and methods in PHP classes. [...] Using the jargon of object-oriented programming, this capacity is widely known as member visibility. This capacity allows PHP programmers to establish whether the set of methods and properties of a specific class will be public, protected, or private.

They start more generally by looking at how to set up the variables globally and then move down the line talking about restrictions (private/protected/public) and how to get to them in the scripts outside the class.

The following are 5 changes you can make to your wordpress blog that can improve your search engine visibility.

The methods on the list are:

• Permalinks
• Create a sitemap
• Improve the titles of your articles
• Site submissions
• Tagging & Meta Keywords

Details are given on each on implementation.