The Scope Resolution Operator( :: )

Global variables are explained outside any functions and thus can be used by all the functions defined thereafter. However, if a global variable is declared with the similar name as that of a local variable of a function , the local variable is the one in the scope when the program implements that function . The C++ language provides the scope resolution operator ( :: ) to access the global variable thus overriding a local variable with the similar name. This operator is prefixed to the name of the global variable . The following example shows its usage.

                int global = 10;

                void main()

                 {

                                int global = 20;

                                printf(" Just writing global prints : %d\n", global);  

printf(" Writing ::global prints : %d\n", ::global);  

 }

The output of this program will be:

 Just writing global prints : 20  

 Writing ::global prints    : 10