Просмотр исходного текста страницы C++/Class/Public

==Assign the public object member address to a pointer==



   
<source lang="cpp">  
#include <iostream>
using namespace std;
class MyClass {
public:
  int i;
  MyClass(int j) { 
     i = j; 
  }
};
int main()
{
  MyClass myObject(1);
  int *p;
  p = &myObject.i;                     // get address of myObject.i
  cout << *p;                          // access myObject.i via p
  return 0;
}

           
         
    
  </source>


==Class with only public fields and methods==


   
<source lang="cpp">   
#include <iostream>
#include <string.h>
using namespace std;
class movie
{
   public:
     char name[64];
     char first_star[64];
     char second_star[64]; 
     void show_movie(void);
     void initialize(char *name, char *first, char *second);
};
void movie::show_movie(void)
{
   cout << "Movie name: " << name << endl;
   cout << "Starring: " << first_star << " and " << second_star << endl << endl;
}
void movie::initialize(char *movie_name, char *first, char *second)
{
   strcpy(name, movie_name);
   strcpy(first_star, first);
   strcpy(second_star, second);
}
int main(void)
{
   movie fugitive, sleepless;
   fugitive.initialize("A", "F", "B");
   sleepless.initialize("C", "D", "E");
   cout << fugitive.name << " and " << sleepless.name << endl;
   cout << fugitive.first_star << endl;
}
  
    
    
  </source>


==field in struct is public by default==


   
<source lang="cpp">   
#include <iostream>
#include <string.h>
using namespace std;
struct MyBook {
  char title[64];  // Public by default
  void show_book(void) 
    {
      cout << "Book: " << title << " Price: $" << price ;  
    };
  
  void set_price(float amount) { price = amount; };
  void assign_title(char *name) { strcpy(title, name); };
  private:
    float price;
};
int main(void)
{
   MyBook book; 
   book.assign_title("A");
   book.set_price(49.95);
   book.show_book();
}
  
    
    
  </source>


==Illustrates the use of a public variable==



   
<source lang="cpp">  
#include <iostream>
using namespace std;
class myclass {
public:
  int i, j, k; // accessible to entire program
};
int main()
{
  myclass a, b;
  a.i = 100; 
  a.j = 4;
  a.k = a.i * a.j;
  b.k = 12; 
  cout << a.k << " " << b.k;
  return 0;
}
           
         
    
  </source>


==public class extending==


   
<source lang="cpp">   
#include <iostream>
#include <string.h>
using namespace std;
class Book 
{
  public:
    Book(char *title) { strcpy(Book::title, title); }; 
    void show_title(void) { cout << title << endl; };
  private:
    char title[64];
};
class LibraryCard : public Book 
{
  public:
    LibraryCard(char *title, char *author, char *publisher) : Book(title) { 
        strcpy(LibraryCard::author, author); 
        strcpy(LibraryCard::publisher, publisher); 
    };
    void show_library(void) { 
        show_title();
        cout << author << " " << publisher; 
  };
  private:
    char author[64];
    char publisher[64];
};

int main(void)
{
   LibraryCard card("A", "B", "C");
   card.show_library();
}
  
    
    
  </source>


==public data field==


   
<source lang="cpp">  
#include <iostream>
using namespace std;
class Base 
{
 public:
   Base(void) { cout << "Base class constructor\n"; };
   int data; 
};
class Derived:public Base 
{
 public:
   Derived(void): Base() 
    { cout << "Derived class constructor\n"; };
};
int main(void)
 {
   Derived object;
   object.data = 5;
   cout << object.data << endl;
 }
  
    
  </source>


==public inheritance from three parent classes==


   
<source lang="cpp">  
#include <iostream>
using namespace std;
class One{
 public:
  One(void) { cout << "Constructor for One\n"; };
};
class Two{
 public:
  Two(void) { cout << "Constructor for Two\n"; };
};
class Three {
 public:
  Three(void) { cout << "Constructor for Three\n"; };
};
class Derived: public One, public Three, public Two 
{
 public:
   Derived(void) : One(), Two(), Three() 
   {
     cout << "Derived constructor called\n"; 
   };
};
int main(void)
{
   Derived my_class;
}
  
    
  </source>


==Virtual public inheritance==


   
<source lang="cpp">  
#include <iostream>
using namespace std;
class base 
{
 public:
   int i;
 };
class derived1 : virtual public base 
{
 public:
   int j;
 };
class derived2 : virtual public base 
{
 public:
   int k;
 };
class derived3 : public derived1, public derived2 {
 public:
   int sum;
};
int main(void)
{
   derived3 object;
   object.i = 10;             // now i is unambiguous
   object.j = 20;
   object.k = 30;
   object.sum = object.i + object.j + object.k;
   cout << object.i << " ";
   cout << object.j << " " << object.k << " ";
   cout << object.sum << endl;
}
  
    
  </source>