Static Class Members

Author: georgecatalin

Section13_Classes_and_Objects/Static_class_members/Player.cpp

@@ -0,0 +1,25 @@
+#include "Player.h"
+
+int Player::number_players {0} ; //initialize the static class member in the .cpp file
+
+Player::Player(std::string name_val, int health_val, int xp_val)
+ : name{name_val},health{health_val},xp{xp_val} 
+{
+ ++number_players;
+}
+
+Player::Player(const Player &source)
+ :Player{source.name,source.health,source.xp}
+{
+ 
+}
+
+Player::~Player()
+{
+ --number_players;
+}
+
+int Player::get_number_players()
+{
+ return number_players; // a static function can only see static members of the class
+}

Section13_Classes_and_Objects/Static_class_members/Player.h

@@ -0,0 +1,29 @@
+#ifndef _PLAYER_H_
+#define _PLAYER_H_
+
+#include <string>
+
+
+class Player
+{
+private:
+ std::string name;
+ int health;
+ int xp;
+ 
+ static int number_players;
+ 
+public:
+ std::string get_name() { return name; }
+ int get_health(){ return health;}
+ int get_xp() {return xp;}
+ 
+ Player(std::string name_val,int health_val=0, int xp_val=0);
+ Player(const Player &source);
+ ~Player();
+ 
+ static int get_number_players();
+
+};
+
+#endif // _PLAYER_H_

Section13_Classes_and_Objects/Static_class_members/main.cpp

@@ -0,0 +1,31 @@
+#include <iostream>
+#include "Player.h"
+
+using namespace std;
+
+
+void display_number_players()
+{
+ cout<<"The number of players is: "<<Player::get_number_players()<<endl;
+}
+
+int main(int argc, char **argv)
+{
+display_number_players();
+ 
+ Player george("George");
+ display_number_players();
+ 
+ {
+ Player kornel("Kornel");
+ display_number_players(); //object kornel will get out of the scope as the {} block ends and gets deleted automatically because it happens on the stack
+ }
+ 
+ display_number_players();
+ 
+ Player *ninja=new Player("Ninja", 100, 35);
+ display_number_players();
+ delete ninja;
+ 
+ display_number_players();
+}