Indholdsfortegnelse for Issue 8 i Coding & Programming The Complete Manual

#INCLUDE <C++ IS ACE!> As you learn the basics of programming, you will begin to understand the structure of a program. The commands may be different, but you will start to see how the code works. C++ Danish student Bjarne Stroustrup invented C++ in 1979, as a part of his Ph.D. thesis. Initially C++ was called C with Classes, which added features to the already popular C programming language while making it a more user-friendly environment. Bjarne Stroustrup, inventor of C++. #INCLUDE The structure of a C++ program can look complex, but once you get familiar with it you’ll begin to see how it flows. Every C++ code begins with a directive, #include <>. The directive instructs the pre-processor to include a section of the standard C++ code. For example:…

LINUX++ There are many different versions of Linux available, for this example we’re using one of the more popular distributions: Linux Mint. However, these steps will work in any Debian-based Linux. STEP 1 The first step with ensuring Linux is ready for your C++ code is check the system and software are up to date. Open a Terminal and enter: sudo apt-get update && sudo apt-get upgrade. Press Return and enter your password. These commands updates the entire system and any installed software. STEP 2 Most Linux distros come preinstalled with all the necessary components to start coding in C++. However, it’s always worth checking to see if everything is present, so still within the Terminal, enter: sudo apt-get install build-essential and press Return. If you have the right components,…

HELLO, WORLD! It’s traditional in programming for the first code to be entered to output the words ‘Hello, World!’ to the screen. Interestingly, this dates back to 1968 using a language called BCPL. STEP 1 We’re going to use Windows 11 and the excellent IDE Code::Blocks for the rest of the C++ code and tutorials in this book. Begin by launching Code::Blocks. When open, click on File > New > Empty File or press Ctrl+Shift+N on the keyboard. STEP 2 Now you can see a blank screen, with the tab labelled *Untitled1, and the number one in the top left of the main Code::Blocks window. Begin by clicking in the main window, so the cursor is next to the number one, and entering: STEP 3 At the moment it doesn’t…

THE DECLARATION OF VARIABLES You can declare a C++ variable by using statements within the code. There are several distinct types of variables you can declare. Here’s how it works. STEP 1 Open up a new, blank C++ file and enter the usual code headers: STEP 2 Start simple by creating two variables, a and b, with one having a value of 10 and the other 5. You can use the data type int to declare these variables. Within the curly brackets, enter: STEP 3 You can build and run the code but it won’t do much, other than store the values 10 and 5 to the integers a and b. To output the contents of the variables, add: The cout << “\n”; part simply places a new line between…

C++ = MC2 The basic mathematical symbols apply in C++ as they do in most other programming languages. However, by using the C++ Math Library, you can also calculate square roots, powers, trig and more. STEP 1 C++’s mathematical operations follow the same patterns as those taught in school, in that multiplication and division take precedence over addition and subtraction. You can alter that though. For now, create a new file and enter: STEP 2 While simple, it does get the old maths muscle warmed up. Note that we used a float for the numbers variable. While you can happily use an integer, if you suddenly started to use decimals, you would need to change to a float or a double, depending on the accuracy needed. Run the code and…

PYTHON POWER Ever since the earliest home computers were available, enthusiasts, users and professionals have toiled away until the wee hours, slaving over an overheating heap of circuitry to create something akin to magic. These pioneers of programming carved their way into a new frontier, forging small routines that enabled the letter ‘A’ to scroll across the screen. It may not sound terribly exciting to a generation that’s used to ultra high-definition graphics and open world, multiplayer online gaming. However, forty-something years ago it was blindingly brilliant. Naturally these bedroom coders helped form the foundations for every piece of digital technology we use today. Some went on to become chief developers for top software companies, whereas others pushed the available hardware to its limits and founded the billion pound gaming…

SQL SQL stands for Structured Query Language. SQL is a standard language for accessing and manipulating databases. Although SQL is an ANSI (American National Standards Institute) standard, there are different versions of the SQL language. However, to be compliant, they all support at least the major commands such as Select, Update and Delete in a similar manner. JAVASCRIPT JavaScript (often shortened to JS) is a lightweight, interpreted, object-oriented language with first class functions. JavaScript runs on the client side of the web, that can be used to design or program how the web pages behave on the occurrence of an event. JavaScript is an easy to learn and also powerful scripting language, widely used for controlling web page behaviour. JAVA Java is the foundation for virtually every type of networked…

C EVERYTHING Due to both the complexity of the language and its power and performance, C++ is often used to develop games, programs, device drivers, and even entire operating systems. Dating back to 1979, the start of the golden era of home computing, C++, or rather C with Classes, was the brainchild of Danish computer scientist Bjarne Stroustrup, while working on his Ph.D. thesis. Stroustrup’s plan was to further the original C language, which had been widely used since the early seventies. C++ proved to be popular among the developers of the 80s, since it was a much easier environment with which to get to grips, and, more importantly, it was 99% compatible with the original C language. This meant that, beyond the mainstream computing labs, regular people who didn’t…

CODE::BLOCKS Code::Blocks is a free C++, C and Fortran IDE that is feature rich and easily extendible with plugins. It’s easy to use, comes with a compiler and has a vibrant community behind it too. STEP 1 Start by visiting the Code::Blocks download site, at www.codeblocks.org/downloads. From there, click on the ‘Download the binary releases’ link to be taken to the latest downloadable version for Windows. STEP 2 There you can see, there are several Windows versions available. The one you want to download has mingw-setup.exe at the end of the current version number. At the time of writing this is: codeblocks-17.12mingw-setup.exe. The difference is that the mingw-setup version includes a C++ compiler and debugger from TDM-GCC (a compiler suite). STEP 3 When you’ve located the file, click on the…

DEVELOPING C++ Here are ten great C++ IDEs that are worth looking into. You can install one or all of them if you like, but find the one that works best for you. ECLIPSE Eclipse is a hugely popular C++ IDE that offers the programmer a wealth of features. It has a great, clean interface, is easy to use and available for Windows, Linux and Mac. Head over to www.eclipse.org/downloads/ to download the latest version. If you’re stuck, click the Need Help link for more information. GNAT The GNAT Programming Studio (GPS) is a powerful and intuitive IDE that supports testing, debugging and code analysis. The Community Edition is free, whereas the Pro version costs; however, the Community Edition is available for Windows, Mac, Linux and even the Raspberry Pi.…

GREETINGS FROM C++ Compiling and executing C++ code from Code::Blocks is extraordinarily easy; it’s just a matter of clicking an icon and seeing the result. Here’s how it’s done. STEP 1 Open Code::Blocks, if you haven’t already, and load up the previously saved Hello World code you created. Ensure that there are no visible errors, such as missing semicolons at the end of the std::cout line. STEP 2 If your code is looking similar to the one in our screenshot, then look to the menu bar along the top of the screen. Under the Fortran entry in the topmost menu you can see a group of icons: a yellow cog, green play button and a cog/play button together. These are Build, Run, Build and Run functions. STEP 3 Start by…

THE VALUE OF DATA There are many different data types available for the programmer in C++, such as an integer, floating point, Boolean, character and so on. It’s widely accepted that there are seven basic data types, often called Primitive Built-in Types; however, you can create your own data types should the need ever arise within your code. The seven basic data types are: These basic types can also be extended using the following modifiers: Long, Short, Signed and Unsigned. Basically this means the modifiers can expand the minimum and maximum range values for each data type. For example, the int data type has a default value range of -2147483648 to 2147483647, a fair value, you would agree. Now, if you were to use one of the modifiers, the range…

HELLO, DAVE You have already used cout, the standard output stream, throughout our code. Now you’re going to be using cin, the standard input stream, to prompt a user response. STEP 1 Anything that you want the user to input into the program needs to be stored somewhere in the system memory, so it can be retrieved and used. Therefore, any input must first be declared as a variable, so it’s ready to be used by the user. Start by creating a blank C++ file with headers. STEP 2 The data type of the variable must also match the type of input you want from the user. For example, to ask a user their age, you would use an integer like this: STEP 3 The cin command works in the…

Python’s ability to create highly readable code, within a small set of instructions, has a considerable impact on our modern digital world. From being an ideal first programmers’ choice through to being able to create interactive stories and games; from scientific applications through to artificial Intelligence and web-based applications, the only limit to Python is the imagination of the person coding in it. It’s Python’s malleable design that makes it an ideal language for many different situations and roles. Even certain aspects of the coding world that require more efficient code still use Python. For example, NASA utilises Python both as a stand-alone language and as a bridge between other programming languages. This way, NASA scientists and engineers are able to get to the data they need without having to…

PYTHON POWER Python is a high-level, general-purpose programming language that was designed by Guido van Rossum in the late ‘80s, as a successor to the ABC Programming Language, and became available to use in 1990. The Python Software Foundation, a non-profit organisation devoted to both furthering and improving Python, currently develops the language. The foundation’s purpose is to “promote, protect, and advance the Python programming language, and to support and facilitate the growth of a diverse and international community of Python programmers.” The structure of Python code has been designed to flow easily, allowing those who are just beginning to code to follow it without too much difficulty. Yet, despite its ease of use, Python is regularly used throughout a number of industries in real-world scenarios. Big Data and AI…

PYTHON PENGUIN Linux is such a versatile operating system that it’s often difficult to nail down just one-way of doing something. Different distributions go about installing software in different ways, so for this particular tutorial we will stick to Linux Mint. STEP 1 First you need to ascertain which version of Python is currently installed in your Linux system. To begin with, drop into a Terminal session from your distro’s menu, or hit the Ctrl+Alt+T keys. STEP 2 Next, enter: python --version into the Terminal screen. You should have the output relating to version 2.x of Python in the display. Most Linux distro come with both Python 2 and 3 by default, as there’s plenty of code out there still available for Python 2. Now enter: python3 --version. STEP 3…

“It’s up to you how far to take your coding adventure!” MORE THAN CODE For those of you old enough to remember the ‘80s, the golden era of home computing, the world of computing was a very different scene to how it is today. 8-bit computers that you could purchase as a whole, as opposed to being in kit form and you having to solder the parts together, were the stuff of dreams; and getting your hands on one was sheer bliss contained within a large plastic box. However, it wasn’t so much the new technology that computers then offered, moreover it was the fact that for the first time ever, you could control what was being viewed on the ‘television’. Instead of simply playing one of the thousands of…

Coding can be one of those experiences that sounds fantastic, but is often confusing to tackle. After all, there’s a plethora of languages to choose from, countless apps that will enable you to code in a specific, or range, of languages and an equally huge amount of third-party software to consider. In addition, by accessing the Internet, you will discover that there are countless coding tutorials available for the language in which you’ve decided you want to program, alongside even more examples of code. It’s all a little too much at first. The trick is to slow down and, to begin with, not look too deeply into coding. Like all good projects, you need a solid foundation on which to build your skillset and to have all the necessary tools…

C++ SETUPS As most, if not all, operating systems have C++ at their code, it stands to reason that you can learn to program in C++ no matter what OS you’re currently using. COMPUTER Unless you fancy writing out your C++ code by hand on a sheet of paper (which is something many older coders used to do), then a computer is an absolute must have component. PC users can have any recent Linux distro or Windows OS, Mac users the latest macOS. AN IDE An IDE is used to enter and execute your C++ code. Many IDEs come with extensions and plugins that help make it work better, or add an extra level of functionality. Often, an IDE will provide enhancements depending on the core OS being used, such…

XCODE Apple’s Xcode is primarily designed for users to develop apps for macOS, iOS, tvOS and watchOS applications in Swift or Objective-C, but we can use it for C++ too. STEP 1 Start by opening the App Store on your Mac, Apple Menu > App Store. In the Search box enter Xcode, and press Return. There will be many suggestions filling the App Store window, but it’s first option, Xcode, that you need to click on. STEP 2 Take a moment to browse through the app’s information, including the compatibility to ensure you have the correct version of macOS. Xcode requires macOS 10.12.6 or later to install and work. STEP 3 When you’re ready, click on the Get or cloud icon button which will install the Xcode app. Enter your…

THE IMPORTANCE OF COMMENTING Comments inside code are basically human readable descriptions that detail what the code is doing at that particular point. They don’t sound especially important but code without comments is one of the many frustrating areas of programming, regardless of whether you’re a professional or just starting out. In short, all code should be commented in such a manner as to effectively describe the purpose of a line, section, or individual elements. You should get in to the habit of commenting as much as possible, by imagining that someone who doesn’t know anything about programming can pick up your code and understand what it’s going to do simply by reading your comments. In a professional environment, comments are vital to the success of the code and ultimately,…

STRING THEORY There are different ways in which you can create a string of characters, which historically are all carried over from the original C language, and are still supported by C++. STEP 1 To create a string you use the char function. Open a new C++ file and begin with the usual header: STEP 2 It’s easy to confuse a string with an array. Here’s an array, which can be terminated with a null character: STEP 3 Build and run the code, and ‘Welcome’ appears on the screen. While this is perfectly fine, it’s not a string. A string is a class, which defines objects that can be represented as a stream of characters and doesn’t need to be terminated like an array. The code can therefore be represented…

WHAT WE’RE USING Thankfully, Python is a multi-platform programming language available for Windows, macOS, Linux, Raspberry Pi and more. If you have one of those systems, then you can easily start using Python. ☐ COMPUTER Obviously you’re going to need a computer in order to learn how to program in Python and to test your code. You can use Windows (from XP onward) on either a 32 or 64-bit processor, an Apple Mac or Linux installed PC. ☐ AN IDE An IDE (Integrated Developer Environment) is used to enter and execute Python code. It enables you to inspect your program code and the values within the code, as well as offering advanced features. There are many different IDEs available, so find the one that works for you and gives the…

INSTALLING PYTHON 3.X Microsoft Windows doesn’t come with Python pre-installed as standard, so you’re going to have to install it yourself manually. Thankfully, it’s an easy process to follow. STEP 1 Start by opening your web browser to www.python.org/downloads/. Look for the button detailing the Download link for Python 3.x. Python is regularly updated, changing the last digit for each bug fix and update. Therefore, don’t worry if you see Python 3.7.0, or more, as long as it’s Python 3, the code in this book will work fine. STEP 2 Click the download button for version 3.x, and save the file to your Downloads folder. When the file is downloaded, double-click the executable and the Python installation wizard will launch. From here you’ll have two choices: Install Now and Customise…

THE POWER OF PI While having a far more powerful coding platform on which to write and test your code is ideal, it’s not often feasible. Most of us are unable to jump into a several hundred-pound investment when we’re starting off and this is where the Raspberry Pi can help out. While having a far more powerful coding platform on which to write and test your code is ideal, it’s not often feasible. Most of us are unable to jump into a several hundred-pound investment when we’re starting off and this is where the Raspberry Pi can help out. The Raspberry Pi is a fantastic piece of modern hardware that has created, or rather re-created, the fascination we once all had about computers, how they work, how to code…