Depending on how you coded the game, the end result should look something like this:
There are many more features you could add to your game if you'd like. For example, every time the player hits an enemy ship you could create a variable called Points which counts the hits and displays them on the screen. You could also create different types of enemy ships in which some are harder to destroy than others. For instance, instead of having Hit as a Boolean variable it could be an Integer counter that doesn't allow the ship to explode until it has reached a certain threshold. The possibilities are endless if you take the time to master the techniques presented up to now. There are of course many more things to learn about programming. Keep in mind that this book is a work in progress so several more units are to follow. For now, if you are interested the best way is to search the internet for tutorials. You know enough of the basics that you should be able to piece together the rest from searching on your own. A great number of languages are free and can be downloaded and installed just as easily as Object Pascal. For developing online games you might want to look into ActionScript 3.0 which is the programming language behind Adobe's Flash player. For more rigorous activities like data analysis you could look to MATLAB (or Octave for the free version) or Python. Developing your own websites would require Javascript and PHP. This assumes of course that you would want to create dynamic content on your website. For static web pages only, you simply need HTML which is not programming at all (it's a document markup language). For native application development Object Pascal is recommended as a very good cross-platform solution; however, you might find that you want to venture into C++ as well. Java is rather bulky for native application development but it works quite well if you need a simple application to run on all platforms with little effort from the programming side. Java also is the language of choice for Google's Android platform. Objective C and C++ are preferred for Apple's iPhone platform.
So, as you can see, there are a great number of languages and platforms to choose from. You must pick the language that best suits your needs. All of these languages contain for loops and if statements. Most have some form of object-oriented capabilities. In every single one, code organization is paramount. So you will be able to apply the skills you have learned here to multiple languages by simply learning the syntax of the new language. That statement comes with one caveat, however. Many languages have their own set of special features which can often be almost completely unique to the language. For example, MATLAB relies heavily on coding values as matrices. This means that you will need to design your program around matrix operations and attempt to minimize the use of for loops (which are actually less efficient in MATLAB for reasons we're not going to discuss here). Python supports both subroutines and coroutines (among many other powerful features). Coroutines are more general than subroutines in that they can yield execution between themselves at arbitrary points in the code. This is in contrast to subroutines in which a call to a subroutine causes execution to descend into the subroutine and then return to the caller. The entry and exit points of subroutines are well defined while a coroutine can have multiple entry and exit points. Thus, there are times that you will have to adjust your conceptual framework in order to program efficiently in a particular language. Training yourself to do this will allow you to utilize a powerful toolset of languages to apply to solving various computer-related tasks. With that said, we wish you the best of luck in learning to program. We hope to see you again when the next unit is complete.
So, as you can see, there are a great number of languages and platforms to choose from. You must pick the language that best suits your needs. All of these languages contain for loops and if statements. Most have some form of object-oriented capabilities. In every single one, code organization is paramount. So you will be able to apply the skills you have learned here to multiple languages by simply learning the syntax of the new language. That statement comes with one caveat, however. Many languages have their own set of special features which can often be almost completely unique to the language. For example, MATLAB relies heavily on coding values as matrices. This means that you will need to design your program around matrix operations and attempt to minimize the use of for loops (which are actually less efficient in MATLAB for reasons we're not going to discuss here). Python supports both subroutines and coroutines (among many other powerful features). Coroutines are more general than subroutines in that they can yield execution between themselves at arbitrary points in the code. This is in contrast to subroutines in which a call to a subroutine causes execution to descend into the subroutine and then return to the caller. The entry and exit points of subroutines are well defined while a coroutine can have multiple entry and exit points. Thus, there are times that you will have to adjust your conceptual framework in order to program efficiently in a particular language. Training yourself to do this will allow you to utilize a powerful toolset of languages to apply to solving various computer-related tasks. With that said, we wish you the best of luck in learning to program. We hope to see you again when the next unit is complete.