I have been reading a lot of tutorials on C++ class but they miss something that other tutorials include.
Can someone please show me how to write and use a very simple C++ class that uses visibility, methods and a simple constructor and destructor?
Well documented example taken and explained better from Constructors and Destructors in C++:
#include <iostream> // for cout and cin
class Cat // begin declaration of the class
{
public: // begin public section
Cat(int initialAge); // constructor
Cat(const Cat& copy_from); //copy constructor
Cat& operator=(const Cat& copy_from); //copy assignment
~Cat(); // destructor
int GetAge() const; // accessor function
void SetAge(int age); // accessor function
void Meow();
private: // begin private section
int itsAge; // member variable
char * string;
};
// constructor of Cat,
Cat::Cat(int initialAge)
{
itsAge = initialAge;
string = new char[10]();
}
//copy constructor for making a new copy of a Cat
Cat::Cat(const Cat& copy_from) {
itsAge = copy_from.itsAge;
string = new char[10]();
std::copy(copy_from.string+0, copy_from.string+10, string);
}
//copy assignment for assigning a value from one Cat to another
Cat& Cat::operator=(const Cat& copy_from) {
itsAge = copy_from.itsAge;
std::copy(copy_from.string+0, copy_from.string+10, string);
}
// destructor, just an example
Cat::~Cat()
{
delete[] string;
}
// GetAge, Public accessor function
// returns value of itsAge member
int Cat::GetAge() const
{
return itsAge;
}
// Definition of SetAge, public
// accessor function
void Cat::SetAge(int age)
{
// set member variable its age to
// value passed in by parameter age
itsAge = age;
}
// definition of Meow method
// returns: void
// parameters: None
// action: Prints "meow" to screen
void Cat::Meow()
{
cout << "Meow.\n";
}
// create a cat, set its age, have it
// meow, tell us its age, then meow again.
int main()
{
int Age;
cout<<"How old is Frisky? ";
cin>>Age;
Cat Frisky(Age);
Frisky.Meow();
cout << "Frisky is a cat who is " ;
cout << Frisky.GetAge() << " years old.\n";
Frisky.Meow();
Age++;
Frisky.SetAge(Age);
cout << "Now Frisky is " ;
cout << Frisky.GetAge() << " years old.\n";
return 0;
}