Take Up Code

Programming involves giving specific instructions but sometimes you want the ability to introduce random behavior. Maybe you want to simulate how a human character sometimes does things in a different order or takes a different path. Or maybe you want the computer to select various items from a collection. Or maybe you want to simulate the randomness of rolling dice. This episode explains how to do this.

What are denial of service attacks? The datacenter that hosts the Take Up Code podcast was put under so much stress due to a coordinated attack that the the entire datacenter had to be taken offline for several days while measures were taken to combat the attack. What happened? And what was done to make it better? That is what I am going to begin explaining today.

C# also supports both implicit and explicit casts and gives you some different choices when you need to switch types. Plus you have a runtime that is ready to throw an InvalidCastException. But even if you do not hit an exception, there are some things you should be aware of. This is still casting.

Can you change an int into a float? And because an int occupies multiple bytes in memory, can you get access to the individual bytes by themselves? Or what if you have a derived class and you want to refer to it as if it was a base class? And can you go the other way, from base class to derived class? These are the topics I will be explaining today.

Declaring methods inside classes is great but what do you do when you want a method you can call anytime? If you are using C++, then just write a method. But if you still want your method in a class or if you are using C# where all methods need to be in classes, then you will need to make your method static. And you can declare static data too. What does that do?

Your classes will likely have data members so how do you work with these data members? Should they be public? Private? Do you let other code access them directly? And what is the difference between a field and a property? This episode will help you get and set your data members.

How are namespaces and include files related and why do we need both?

Interfaces give you the ability to define behavior without actually implementing it. Why would you want to do that? Your classes can then declare support for interfaces which means that they promise to support that behavior. How your classes do this is up to them. Declaring support for an interface signals that they do this. You can have what might be completely unrelated classes all supporting the same interface which then allows you to work with them in the same way.

What if you were writing a class that you wanted to be a base class? A class designed from the very beginning to bring together other classes with common behavior. What if you also wanted to guarantee that this class could never be created by itself? That it must always exist as a base class for some other class? All you have to do is make your class abstract. Then it can only be instantiated as part of another class that derives from your class. This episode will explain why you might want to do this and how.

Composition allows you to specify very different kinds of relationships between classes. This is sometimes also called containment. If you are building a racing game and have a car class and a wheel class, you would not want to say that cars are wheels but instead that cars have wheels. Proper use of composition will even allow you to substitute what kind of wheels your cars have. This can not only simplify your designs but make your code easier to test.