In the previous two lessons, we’ve looked at two types of object composition, composition and aggregation. Object composition is used to model relationships where a complex object is built from one or more simpler objects (parts). In this lesson, we’ll take a look at a weaker type of relationship between …
Life is full of recurring patterns, relationships, and hierarchies between objects. By exploring and understanding these, we can gain insight into how real-life objects behave, enhancing our understanding of those objects. For example, let’s say one day you’re walking down the street, and you see a bright yellow object attached …
In this chapter, we explored topics related to operator overloading, as well as overloaded typecasts, and topics related to the copy constructor. Summary Operator overloading is a variant of function overloading that lets you overload operators for your classes. When operators are overloaded, the intent of the operators should be …
The copy assignment operator (operator=) is used to copy values from one object to another already existing object. Related content As of C++11, C++ also supports “Move assignment”. We discuss move assignment in lesson . Copy assignment vs Copy constructor The purpose of the copy constructor and the copy assignment …
In lesson , we introduced type conversion and the concept of implicit type conversion, where the compiler will implicitly convert a value of one type to a value of another type as needed if such a conversion exists. This allows us to do things like this: #include <iostream> void printDouble(double …
Way back in lesson , we discuss 6 basic types of initialization for objects with fundamental types: int a; // no initializer (default initialization) int b = 5; // initializer after equals sign (copy initialization) int c( 6 ); // initializer in parentheses (direct initialization) // List initialization methods (C++11) …
In the previous lesson, we overloaded operator+ as a friend function: #include <iostream> class Cents { private: int m_cents{}; public: Cents(int cents) : m_cents{ cents } {} // add Cents + Cents using a friend function friend Cents operator+(const Cents& c1, const Cents& c2); int getCents() const { return m_cents; …
Most programs that have a user interface of some kind need to handle user input. In the programs that you have been writing, you have been using std::cin to ask the user to enter text input. Because text input is so free-form (the user can enter anything), it’s very easy …
The concepts of scope, duration, and linkage cause a lot of confusion, so we’re going to take an extra lesson to summarize everything. Some of these things we haven’t covered yet, and they’re here just for completeness / reference later. An identifier’s scope determines where the identifier can be accessed …
In lesson , we noted that a variable or function identifier can only have one definition (the one definition rule). Thus, a program that defines a variable identifier more than once will cause a compile error: int main() { int x; // this is a definition for variable x int …
