OOP with C++ and Java

    As a student, I tend to stay in line with what topics and methods that were first taught to me at a young age. As I grew, learning new things from different sources of information, the quirk of curiosity grew in my ever-expanding arsenal of traits and identity. Going into the field of software development, the majority of what I thought revolved around using the programming language we all are familiar with, named Java.

    All of us students of SAIT have come learn a lot about Java, either adoring or hating it at the end. However, there is a plethora of other programming languages such as Python and JavaScript. C++ is the language that has peeked my interest as its predecessors in the C family have existed since the 70s. Out of curiosity, I wondered how different will making object oriented programs be between Java and C++. Allow me to share my journey in quelling said curious thought.

    If you are using Visual Studio Code as your IDE to code with C++, make sure to have a compiler like MinGW installed in your system and have extensions installed in VSC to compile a C++ file. Would recommend watching this video in how to do it:

Link: (https://www.youtube.com/watch?v=9VE7p-he4fA)

    How I first started coding C++ is watching a video on a beginner’s course to C++. Out of the numerous tutorial videos on YouTube, I chose to watch this:

Link:(https://www.youtube.com/results?search_query=c%2B%2B+for+beginners)

    This video showed me how different C++ makes their main driver class, or main function as it was called in the video. It starts with an import of a library called <iostream> using the #include keyword. This library is a header file library that lets me work with input and output of objects. The next like is the data type and the name of the main function of the program. As seen in the picture below:

    While comparing it to how Java must be made to make its main driver class, C++ makes theirs very compact and straight to the point:

    We can at least be relieved that the way coding blocks are formatted is very similar to Java’s and most other static programming languages. One thing majorly different is not having a class name be the same as the file name. Having a different name does not affect the compiling and running of the file.

    The first line of code I learned was what every coder learns in their first ever experience with a programming language, printing out “Hello World” into a console or terminal window. Here is how we first learned to do that exercise in Java:

    For C++, the difference is apparent on how it looks. It confused me as to why it was structured this way, seeing as I was used to the Java coding structure and format. This is how one writes the code to print “Hello World” to the console:

    To break it down: There is a thing called namespace which is a declarative region that provides a scope to the identifiers inside it. The ‘std’ means standard, which refers to the C++ standard library. The double colon (::) is a scope operator that tells the compiler which class/namespace to look in for an identifier. The ‘cout’ syntax means character output, which is used along with the insertion operator (<<) to display a stream of characters. Though writing std on every comment line for printing a statement is kind of a pain and not clean looking for the code. A trick I learned is writing this below the import iostream line so you don’t need to put std for every print line:

    Now that I had a grasp of the naming convention, format and syntaxes that C++ uses, I tried to look into how this programming language makes object oriented programs and comparing it to how Java makes it. Having read through simple guides to start C++ OOP and watching through many tutorial videos, this one taught and explained the topic the best in my opinion:

Link: (https://www.youtube.com/watch?v=wN0x9eZLix4)

    In my learning experience, the concepts that revolve around OOP, which is encapsulation, abstraction, inheritance and polymorphism, all have the same rules on how it works between C++ and Java. However, some basic concepts that we learned in Java are not the same. An example that surprised me while learning is that, while Java can only have 1 public class within a text file, C++ can have multiple public classes within a text file. One last thing to add is that you need to add a semi colon (;) at the end bracket of a class. If that is missing, it will not compile.

    Like Java, C++ also has 3 access modifiers: Public, Private and Protected. The difference though between Java and C++ regarding these modifiers is how they are implemented within a class or method. Instead of putting the modifier along with the name of the class, one must put those modifiers in a certain area within the body of the class or method. As seen in this example:

    I actually liked this method more than specifically putting the access modifiers to each variable or method because it is easier to see which are allowed for public use, which ones are private and should only be used within a class, and which ones are protected and can only be viewed by any following subclasses of the superclass.

    Encapsulation and Inheritance works the same Java, such as one can privatize variables and set getters and setters to retrieve the values of said variables, although the formatting for how inheritance works is a bit different compared to how Java does it. To have a class inherit to a parent class, one just needs to put a colon then the name of the parent class.

    The added public access modifier next to the parent class in the image above allows the child class, named the Teacher class, to be able to access methods that is within the parent class named Employee. The addition is necessary because when a class is created, it is private by default. One also needs to put an inheritance line next to the child class’s constructor to use the parent class’s constructor.

    The program I followed in making through the example that the programmer in the video made does show what C++ can do using OOP and how one can use it. While the formatting and the way of syntax is quite different, along with its naming conventions, the overall functions of OOP is very similar to Java, so one who wants to get into C++ using OOP would be able to pick this up quick.

    I have only scratched the surface of the potential of C++. Only in OOP but its many features that may not be in Java. The faster processing and the simplicity of code format has also left me wanting to learn more about the programming language, and I would recommend for any reader of this blog to do the same. Don’t be intimidated by any of the more advance features of C++, but take it slow and have fun while you are trying to learn all that you can. Thank you reader and I hope you can share my curious experience.