C++/Class/Class Member

Assign values using the member initialization syntax

<source lang="cpp">

1. include <iostream>

using namespace std; class MyClass {

 const int numA; // const member
 const int numB; // const member

public:

 // Initialize numA and numB using initialization syntax.
 MyClass(int x, int y) : numA(x), numB(y) { }
 int getNumA() { 
    return numA; 
 }
 int getNumB() { 
    return numB; 
 }

}; int main() {

 MyClass object1(7, 9), object2(5, 2);
 cout << "Values in object1 are " << object1.getNumB() << " and " << object1.getNumA() << endl;
 cout << "Values in object2 are " << object2.getNumB() << " and " << object2.getNumA() << endl;
 return 0;

}

 </source>

enum field

<source lang="cpp">

1. include <iostream>

using namespace std; enum Days { Monday, Tuesday, Wednesday, Thursday, Friday }; class MyClass {

 public:
   int *lucky_number;
   enum Days lucky_day;

};

int main(void) {

  MyClass wow;
  int lucky = 1500;
  wow.lucky_day = Monday; 
  
  wow.lucky_number = &lucky;
  cout << *(wow.lucky_number) << endl;
  switch (wow.lucky_day) 
  {
    case Monday: cout << "Monday\n";
                 break;
    default: cout << "My lucky day ain"t any day but Monday\n";   
  };

}

 </source>

getName member function reads from the name member variable and the setName member function writes to it

<source lang="cpp">

1. include <iostream>
2. include <string>

using namespace std; class Person {

  private:
     string name; 
     int height;      
  public:
     string getName() const;
     void setName(string);
     int getHeight() const;
     void setHeight(int);

};

  string Person::getName() const
  { return name; }
  void Person::setName(string s)
  { 
     if (s.length() == 0)
        name = "No name assigned";
     else
        name = s; 
  }
  int Person::getHeight() const
  { return height; }
  void Person::setHeight(int h)
  { 
     if (h < 0)
        height = 0;
     else
        height = h; 
  }

void setValues(Person&); void getValues(const Person&); int main () {

  Person p1;
  setValues(p1);  
  cout << "Outputting person data\n";
  getValues(p1);
  return 0;

} void setValues(Person& pers) {

  string str;
  int h;
  cout << "Enter person"s name: ";
  getline(cin,str);
  pers.setName(str);
  cout << "Enter height in inches: ";
  cin >> h;
  cin.ignore();
  pers.setHeight(h);

} void getValues(const Person& pers) {

  cout << "Person"s name: " << pers.getName() << endl; 
  cout << "Person"s height in inches is: " <<         pers.getHeight() << endl;  

}

 </source>

The Member Initialization Syntax

<source lang="cpp">

1. include <iostream>

using namespace std; class MyClass {

 int numA;
 int numB;

public:

 MyClass(int x, int y) {
   numA = x;
   numB = y;
 }
 int getNumA() { 
   return numA; 
 }
 int getNumB() { 
   return numB; 
 }

}; int main() {

 MyClass object1(7, 9), object2(5, 2);
 cout << "Values in object1 are " << object1.getNumB() << " and " << object1.getNumA() << endl;
 cout << "Values in object2 are " << object2.getNumB() << " and " << object2.getNumA() << endl;
 return 0;

}

 </source>

Use class name to reference field name

<source lang="cpp">

1. include <iostream>
2. include <iomanip>
3. include <string.h>
4. include <stdlib.h>

using namespace std; class Book {

 public: 
   Book(char *title, char *author, char *publisher, float price);
   Book(void);
   void show_title(void) { cout << title << "\n"; };
   float get_price(void) { return(price); };
   void show_book(void){ 
     show_title(); 
     show_publisher();
   };
 private:
   char title[256];
   char author[64];
   float price;
   char publisher[256];
   void show_publisher(void) { cout << publisher << "\n"; };

}; Book::Book(char *title, char *author, char *publisher, float price)

{
  strcpy(Book::title, title);
  strcpy(Book::author, author);
  strcpy(Book::publisher, publisher);
  Book::price = price;
}

Book::Book(void)

{
  cerr << "You must specify initial values for Book instance\n";
  exit(1);
}

int main(void)

{
  Book tips("A", "B","C", 49.95);
  Book diary;
  tips.show_book();
  diary.show_book();
}
 
   
   
 </source>