"While" and "Do-While" Loops

I have started into a book that I picked up from the library entitled
Beautiful Code published by O'Rielly Press. It's a compilation of top programmers thoughts on some of the most beautiful code that they have written and the logic and theory behind it. I was slightly apprehensive that it would be way over my head, having no formal training in the field. I'm understanding about 75 - 85% of the discussion so far. What is really insightful, however, are the explanations as to why and what makes their code samples so effective. Hopefully by the end I'll be thinking just a bit more like a programmer.

Today's reading has me thinking about "Do-While" loops, as there was one implemented in the code that I was studying. I'm studying them out in PHP as that is the language that I work in. The online PHP manual has been very helpful in providing some effective examples.

There is one key difference between "Do-While" loops and "While" that I have observed. Both loops have a true/false statement to determine whether the loop is to be processed. The distinction between the two is that in a normal "While" loop that check is performed at the beginning of the loop. This makes is so that the first time the statement is checked the return value must be true or else the while loop will not be executed.

On the contrary, with a "Do-While" loop,  all scripts inside the loop are executed  at least once before the statement is checked. I hope to experiment with this a little more and then report back on how I've found this variation to be helpful.

This example illustrates a quick way of executing a "Do-While" loop without curly brackets.

Encapsulation in OOP

(If you are finding this via a search results, be forewarned: I'm just learning this concept.)

Encapsulation: The practice in Object Oriented Programming of taking functionality and hiding it behind the scenes, so that it works seamlessly without the class user knowing how it is being accomplished.

As I'm thinking about this principle, it occurs to me that there is are abundant examples of encapsulation in use around me every day in my front-end programming work. For example, these days I rely heavily on Jquery to execute Javascript functionality. Jquery seems to me to be the perfect example of making Javascript work "behind the scenes" so that I haven't had to learn to detailed intricacies of Javascript and it's quirky browser specific behaviors.

And yet even more so, with Jquery itself there are more examples of encapsulation. For example, the .show() method, which is actually doing some other more advanced jquery execution, all behind the scenes without me knowing (yet) how it is being accomplished.

Notes on Object Oriented Programming in PHP - Classes and Class Attributes

Classes, which are the abstracted form of objects, have methods and attributes which in regular programming would be very similar to functions and variables. 

-How Attributes vary from Variables:
They have visibility and must be constants. Yet it is not required that an attribute possess a value to begin with. The key is that attributes can be declared with a variable as the value, it must be either empty (which would be its assigned value) or a pre-defined constant.