Programming Corner

We are up to 40 keywords covered in previous articles! That's 83% keywords covered. We have only 8 keywords to cover and I will be covering 1 of those in this article. We are almost done with all the basic keywords. This article will illustrate the use of the keyword super . I suggest you start with Java Keywords (Part I) before proceeding further, if you have not read any of the previous articles in the Java Keyword series. Also, go back and read the one about Data Types. All of these articles are from September 2018. That should help you find them quickly. You can also use the "search" option at the top of this page. The series was written with natural progression in mind. Therefore, some of the keywords already covered may be used in code examples illustrated here. Java keyword list abstract continue for new switch assert default goto * package synchronized boolean do if private this break double implements protected throw ...

We are up to 39 keywords covered in previous articles! That's 81% keywords covered. We have only 9 keywords to cover and I will be covering 1 of those in this article. We are almost done with all the basic keywords. This article will illustrate the use of the keyword this . I suggest you start with Java Keywords (Part I) before proceeding further, if you have not read any of the previous articles in the Java Keyword series. Also, go back and read the one about Data Types. All of these articles are from September 2018. That should help you find them quickly. You can also use the "search" option at the top of this page. The series was written with natural progression in mind. Therefore, some of the keywords already covered may be used in code examples illustrated here. Java keyword list abstract continue for new switch assert default goto * package synchronized boolean do if private this break double implements protected throw ...

We are up to 38 keywords covered in previous articles! That's 79% keywords covered. We have only 10 keywords to cover and I will be covering 1 of those in this article. We are almost done with all the basic keywords. This article will illustrate the use of the keyword instanceof . I suggest you start with Java Keywords (Part I) before proceeding further, if you have not read any of the previous articles in the Java Keyword series. Also, go back and read the one about Data Types. All of these articles are from September 2018. That should help you find them quickly. You can also use the "search" option at the top of this page. The series was written with natural progression in mind. Therefore, some of the keywords already covered may be used in code examples illustrated here. Java keyword list abstract continue for new switch assert default goto * package synchronized boolean do if private this break double implements protected ...

Before we start... Let me start by saying this: NEVER dismiss an idea without giving it any consideration. That was the mistake I made when I first encountered an article about this design pattern many years ago. I was thrown off by the name and without even attempting to find out what this design pattern was all about, I moved on to other things. That was a huge mistake and I am not afraid to admit it. I urge you not to make that mistake. And if you have already, never make that mistake again. Trust me, you will thank me later. For now, let me tell you my story and attempt to explain when to use it along with a simple example on how to implement this pattern. The Null Object Pattern By definition, the main purpose of this pattern is to have an Object-Oriented alternative to the absence of objects by creating objects that display "do nothing" behavior. That sounds like a mouthful. In simplest terms, it is meant to provide a mechanism to replace null references w...

EDITORIAL NOTE : This article was published briefly back in 2016 and quickly set back to draft because I wasn't happy with its contents. It is a shame that it was taking me three years to revisit this topic and work on a new and improved version. At least, I'm hoping it will be to the liking you the reader. Keep in mind that the opening paragraph will still read as if I just wrote it for my (former) students at Texas Wesleyan. I started working on lecture on the topic of Object-Oriented (OO) Programming by gathering some material, old and new, when I realized this might be good and simple post for my second attempt at blogging. To be completely honest, in the 8 hours I spent collecting information and preparing material for this week's lecture, I realized I still made some of the mistakes I am about to blog about. I am actually hoping I can write a series of postings regarding Object-Oriented Programming (OOP). But to do so, I must start from the very beginning. ...

I was watching a video today where this topic was brought up and I was kind of surprised at how some people categorize the importance of packages in Java. I will go over two main reasons why packages are important. Before I got into details, let start by enumerating the two reasons I am discussing in this blog. The first, and most common reason, is for organization purposes. I am sure you have heard this many times. The second reason, and the one I believe is badly overlooked, is protection to restrict access to your classes and features. Use packages to organize your classes and features The first point you should know about packages is that packages are basically the folders where your classes reside. This concept should not be foreign to anyone. If you have used a computer at least once in your life, you should already be aware why folders are helpful in keeping your files organized. If you are like me, you love to create folders to keep your files organized and to quickly...

I believe this is the most important aspect of Object-Oriented Design (OOD) and Programming (OOP). I also believe this is the most disregarded. It is disregarded because it is not fully understood. It is my opinion that this aspect of OOP is misunderstood because beginner programmers focus in learning WHAT encapsulation is, and not why it is important or needed. This article aims to explain why encapsulation is important and how to achieve true encapsulation. Although anyone could look up its definition in a dictionary, I would like to start by defining the word 'encapsulation.' Encapsulation simply means to enclose something in. To completely cover or hide something especially so that it will not touch (or come in contact with) anything else. In the real world, there are many reasons to encapsulate. For example, certain medication come in the form of capsules. The real value of medicinal capsules in in the medicine that it encloses. To make a long story short, med...

When determining the relationship between object at design time, it is easy to succumb to the habit of using inheritance; simply because it is easy.  In a language such as C++, it is even easier to do so because the language supports multiple inheritance. Figure  1 : the java.util. List  Interface Assume that Java does not have a Stack (java.util.Stack) class and you need to create a custom stack (call it MyStack).  You could do this in three different ways, but for the purposes of this paper I will discard the creation of the Stack class as shown in the image above.  Therefore, assume that there are only two ways.  The first way is to extend the ArrayList class.  The second way is to include an ArrayList object as a data member.  The first solution uses inheritance to solve the problem.  Remember, inheritance establishes an “is-a” relationship between objects.  Therefore, the relationship between MyStack...

A question was raised on LinkedIn (you can follow me there: https://www.linkedin.com/in/hector-fontanez ) that got me thinking and I decided to blog about it. I am going to start by defining what generalization means in Object-Oriented Programming (OOP) and Design (OOD). Generalization in OOD implies that a specialized (child) class is based on a general (parent) class. This, in turn, implies a "is-a" relationship. When you analyze the object types and their relationships as depicted in the image above, from left to right, it goes from very general to more specific. You could say that an Animal "is a" more general form of Dog, of Canine, and even than Mammal. Likewise, a Canine "is a" more general form of Dog. If you analyze it from right to left, the opposite happens: it goes from more specific to more general. Put in other terms, the type gets broadened. Therefore, you can still refer to dogs as canines, mammals, or even animals. ...