C++ Class
- Define a class
class CBox
{
// public data members
public:
double m_Length;
double m_Breadth;
double m_Height;//Constructor
CBox(double lv = 1.0, double bv = 1.0, double hv = 1.0)
{
m_Length = lv;
m_Breadth = bv;
m_Height = hv;
}// Same as above
CBox(double lv = 1.0, double bv = 1.0, double hv = 1.0) : m_Length(lv), m_Breadth(bv), m_Height(hv)
{
}// member function
double Volume()
{
return m_Length * m_Breadth * m_Height;
}
}; // Don't forget this semicolon
- Access modifiers
- public
- protected
- private //Default
- static
- Constant object of class
- No changes allowed to the object after instantiation
- Examle
- const CBox standardBox(3.0,5.0,8.0);
- Costant object can only access constant member function
- int Compare(CBox box) const {…};
- Should declare all member functions that do not alter the class object as const
- Methods with same signatures except const are consider two different methods
- Instantiate class
- CBox box1;
- CBox box2;
- CBox box3(10.0, 20.0, 30.0);
- Access member data
- Access member functions
- Pointer to class
- CBox box1(1.0, 2.0, 3.0);
- CBox* pBox1 = &box1;
- pBox1->Volume();
- Class reference
- Complex class object should be pass as reference to avoid copying
- CBox(const CBox& initB);
- Destructor
- ~CBox();
- Always implement a copy constructor if you dynamically allocate memory for class members
// Copy Constructor definition
CMessage(const CMessage& initM)
{
// Allocate space for text
pmessage = new char[ strlen(initM.pmessage) + 1 ];
// Copy text to new memory
strcpy(pmessage, initM.pmessage);
}
- Exercise
- Create a new project
- File -> New -> Projects -> Win32 Console Application
- Create a new class
- In Class View
- Right click Classes -> New Class -> MyClass
- Two files are created
- MyClass.cpp
- Contains class implementations
- MyClass.h
- Contains class definition
- Add data members
- Add inline function members (short functions)
- Add other function members
- Add function prototype to header file
- Add function implementation to cpp file
- Add global functions to support MyClass operations
- File -> New -> C++ Source File -> MyClassOperations.cpp
- Add new header file for MyClassOperations.cpp
- File -> New -> C++ Header File -> MyClassOperations.h
- Use MyClass in main() function
- #include MyClass.h
- #include MyClassOperations.h
This entry was posted in
cpp. Bookmark the
permalink.
