In the lesson , we introduced global variables, and in lesson , we introduced static local variables. Both of these types of variables have static duration, meaning they are created at the start of the program, and destroyed at the end of the program. Such variables keep their values even …
In lesson , you learned that objects of a fundamental data type (int, double, char, etc…) can be made constant via the const keyword. All const variables must be initialized at time of creation. const int x; // compile error: not initialized const int y{}; // ok: value initialized const …
All of the classes that we have written so far have been simple enough that we have been able to implement the member functions directly inside the class definition itself. For example, here’s a simple Date class where all member functions are defined inside the Date class definition: #include <iostream> …
Whenever possible, we want to reduce redundant code (following the DRY principle — Don’t Repeat Yourself). Consider the following functions: void A() { // statements that do task A } void B() { // statements that do task A // statements that do task B } Both functions have a …
One of the questions about classes that new programmers often ask is, “When a member function is called, how does C++ keep track of which object it was called on?”. First, let’s define a simple class to work with. This class encapsulates an integer value, and provides some access functions …
A destructor is another special kind of class member function that is executed when an object of that class is destroyed. Whereas constructors are designed to initialize a class, destructors are designed to help clean up. When an object goes out of scope normally, or a dynamically allocated object is …
When a class type is an aggregate, we can use aggregate initialization to initialize the class type directly: struct Foo // Foo is an aggregate { int x {}; int y {}; }; int main() { Foo foo { 6, 7 }; // uses aggregate initialization return 0; } Aggregate …
In previous lesson , we discussed the public and private access levels. As a reminder, classes typically make their data members private, and private members can not be directly accessed by the public. Consider the following Date class: #include <iostream> class Date { private: int m_year{ 2020 }; int m_month{ …
Let’s say you’re walking down the street on a brisk autumn day, eating a burrito. You want somewhere to sit, so you look around. To your left is a park, with mowed grass and shade trees, a few uncomfortable benches, and screaming kids on the nearby playground. To your right …
In lesson , we introduced the struct program-defined type, which can contain member variables. Here is an example of a struct used to hold a date: struct Date { int year {}; int month {}; int day {}; }; Now, if we want to print the date to the screen …
