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RationalDB Database Design
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Lesson 3
Objective
The scope resolution operator
Unary form of the scope resolution operator.
   
The scope resolution operator's unary form is used to access a variable or object that is at external scope and that has been "hidden" by an identically named variable or object declared at local or class scope.
int count = 0;        //external variable
 void how_many(double w[], double x, int& count)
{
    for (int i = 0; i < N; ++i)
      count += (w[i] == x);
    	++ ::count;         //keep track of calls
}
Example of unary scope resolution operator
#include <iostream>
using namespace std;

int n = 5; 

int main()
{
   double n = 11.7;

   cout << "Local double value of n = " << n
      << "\nGlobal int value of n = " << ::n << endl;
   return 0;
}
Local double value of n = 11.7
Global int value of n = 5
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