And so our journey through C++’s inheritance and virtual functions comes to an end. Fret not, dear reader, for there are plenty of other areas of C++ to explore as we move forward. Chapter summary C++ allows you to set base class pointers and references to a derived object. This …
Consider the following program that makes use of a virtual function: #include <iostream> class Base { public: virtual void print() const { std::cout << “Base”; } }; class Derived : public Base { public: void print() const override { std::cout << “Derived”; } }; int main() { Derived d{}; Base& …
Way back in lesson , we examined the concept of casting, and the use of static_cast to convert variables from one type to another. In this lesson, we’ll continue by examining another type of cast: dynamic_cast. The need for dynamic_cast When dealing with polymorphism, you’ll often encounter cases where you …
Let’s go back to an example we looked at previously: class Base { protected: int m_value{}; public: Base(int value) : m_value{ value } { } virtual const char* getName() const { return “Base”; } int getValue() const { return m_value; } }; class Derived: public Base { public: Derived(int value) …
You’ve probably seen this program in a lot of textbooks and tutorials: #include <iostream> using namespace std; int main() { cout << “Hello world!”; return 0; } Some older IDEs will also auto-populate new C++ projects with a similar program (so you can compile something immediately, rather than starting from …
Let’s say you are driving to a friend’s house for the first time, and the address given to you is 245 Front Street in Mill City. Upon reaching Mill City, you take out your map, only to discover that Mill City actually has two different Front Streets across town from …
To address some common challenges with inheritance, there are two special identifiers: override and final. Note that these identifiers are not considered keywords — they are normal identifiers that have special meaning in certain contexts. Although final isn’t used very much, override is a fantastic addition that you should use …
Inheritance allows us to model an is-a relationship between two objects. The object being inherited from is called the parent class, base class, or superclass. The object doing the inheriting is called the child class, derived class, or subclass. When a derived class inherits from a base class, the derived …
In this chapter, we learned about some different kinds of relationships between two objects. Summary The process of building complex objects from simpler ones is called object composition. There are two types of object composition: composition, and aggregation. Composition exists when a member of a class has a part-of relationship …
So, you’ve written a program, it compiles, and it even appears to work! What now? Well, it depends. If you’ve written your program to be run once and discarded, then you’re done. In this case, it may not matter that your program doesn’t work for every case — if it …
