From RubySource.com there's a new post from a confessed developer who moved from PHP to Ruby about PHP's private visibility rules and how they compare to Ruby's.

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.

If you were a fan of the PHP quizes that Mark van der Velden has posted in the past, you'll be happy to know he's come back with part four of the series after a bit of a hiatus.

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.

Wes Shell has posted a new tutorial to his blog today looking at encapsulation in PHP development - containing parts of the script to make them easier to work with as a whole.

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.

In this recent post to his blog Chance Garcia looks at visibility and inheritance in PHP applications. Specifically, it references a question that came up on IRC about the "default" visibility for methods and the open/closed principle.

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.

DevShed finishes off their series looking a private, public and protected variables and methods in classes with this final look a private methods in PHP5 object-oriented programming.

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.

DevShed continues their series looking at variable scoping in PHP5 classes with this new look at using the public and protected keywords to "restrict member visibility".

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.

DevShed has posted the latest in their series of tutorials covering the scoping keywords in PHP5 (public, private and protected). In this latest edition they work with private values from a parent 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.

DevShed continues their look at the use of the member visibility functionality PHP5 offers in its classes with this new part of the series, a look at the private property.

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.

In this new tutorial posted to DevShed, they take a look at working with classes in PHP5, specifically using the keywords for "member visibility" to make your classes a bit more structured.

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 JSLabs blog has five quick tips for WordPress users out there on how to make their blogs a bit more "search engine friendly".

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.