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Scope resolution operator in C++

Scope resolution operator (::) in C++ is used to define a function outside a class or when we want to use a global variable but also has a local variable with the same name.

C++ programming code

#include <iostream>

using namespace std;
 
char c = 'a';     // global variable (accessible to all functions)
 
int main() {
  char c = 'b';   // local variable (accessible only in main function)
 
  cout << "Local  variable: " << c << "\n";      
  cout << "Global variable: " << ::c << "\n";  // Using scope resolution operator
 
  return 0;
}

Output of program:
Scope resolution operator in C++ variable program output.

Scope resolution operator in class

#include <iostream>
using namespace std;

class Game {
public:
  void play();  // Function declaration
};

// function definition outside the class

void Game::play() {
  cout << "Function defined outside the class.\n";
}

int main() {
  Game g;
  g.play();

  return 0;
}

Output of program:
Scope resolution operator in C++ class program output.

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