In the previous lesson , we noted that object composition is the process of creating complex objects from simpler ones. We also talked about one type of object composition, called composition. In a composition relationship, the whole object is responsible for the existence of the part. In this lesson, we’ll …
In real-life, complex objects are often built from smaller, simpler objects. For example, a car is built using a metal frame, an engine, some tires, a transmission, a steering wheel, and a large number of other parts. A personal computer is built from a CPU, a motherboard, some memory, etc… …
In the previous lessons ( and ), you learned how to use the debugger to watch the path of execution through your program. However, stepping through a program is only half of what makes the debugger useful. The debugger also lets you examine the value of variables as you step …
When you run your program, execution begins at the top of the main function, and then proceeds sequentially statement by statement, until the program ends. At any point in time while your program is running, the program is keeping track of a lot of things: the value of the variables …
In the previous lesson, for simplicity, we initialized our class member data in the constructor using the assignment operator. For example: class Something { private: int m_value1 {}; double m_value2 {}; char m_value3 {}; public: Something() { // These are all assignments, not initializations m_value1 = 1; m_value2 = 2.2; …
Shallow copying Because C++ does not know much about your class, the default copy constructor and default assignment operators it provides use a copying method known as a memberwise copy (also known as a shallow copy). This means that C++ copies each member of the class individually (using the assignment …
Recapping the types of initialization Since we’re going to talk a lot about initialization in the next few lessons, let’s first recap the types of initialization that C++ supports: direct (parenthesis) initialization, uniform (brace) initialization or copy (equals) initialization. Here are examples of all of those, using our Fraction class: …
In lesson , you learned that C++ allows you to convert one data type to another. The following example shows an int being converted into a double: int n{ 5 }; auto d{ static_cast<double>(n) }; // int cast to a double C++ already knows how to convert between the built-in …
All of the overloaded operators you have seen so far let you define the type of the operator’s parameters, but not the number of parameters (which is fixed based on the type of the operator). For example, operator== always takes two parameters, whereas operator! always takes one. The parenthesis operator …
In lesson , we covered many types of common C++ semantic errors that new C++ programmers run into with the language. If an error is the result of a misused language feature or logic error, the error can simply be corrected. But most errors in a program don’t occur as …
