A function is a piece of code that is called by name. It can be passed data to operate on (i.e. the parameters) and can optionally return data (the return value). All data that is passed to a function is explicitly passed. A method is a piece of code that is called by a name that is associated with … Read more
What are you using to compile this? If there’s an undefined reference error, usually it’s because the .o file (which gets created from the .cpp file) doesn’t exist and your compiler/build system is not able to link it. Also, in your card.cpp, the function should be Card::Card() instead of void Card. The Card:: is scoping; … Read more
The differences between a class and a struct in C++ is: struct members and base classes/structs are public by default. class members and base classes/struts are private by default. Both classes and structs can have a mixture of public, protected and private members, can use inheritance and can have member functions. I would recommend you: … Read more
In this code: … the self variable represents the instance of the object itself. Most object-oriented languages pass this as a hidden parameter to the methods defined on an object; Python does not. You have to declare it explicitly. When you create an instance of the A class and call its methods, it will be passed automatically, as in … Read more
A great example illustrating LSP (given by Uncle Bob in a podcast I heard recently) was how sometimes something that sounds right in natural language doesn’t quite work in code. In mathematics, a Square is a Rectangle. Indeed it is a specialization of a rectangle. The “is a” makes you want to model this with inheritance. However if … Read more
The Inversion of Control (IoC) and Dependency Injection (DI) patterns are all about removing dependencies from your code. For example, say your application has a text editor component and you want to provide spell checking. Your standard code would look something like this: What we’ve done here creates a dependency between the TextEditor and the … Read more
The benefits of super() in single-inheritance are minimal — mostly, you don’t have to hard-code the name of the base class into every method that uses its parent methods. However, it’s almost impossible to use multiple-inheritance without super(). This includes common idioms like mixins, interfaces, abstract classes, etc. This extends to code that later extends yours. If somebody … Read more