#include <iostream.h>
/********************************************************
 An example to demonstrate the scope
 of variables
********************************************************/

void fn(char , long );
int z = 25;
main(){
	long x = 100;
	float y = 6.2897;
	char c = 'a';
	double z = 3.145;
	cout << "Inside main\n";
	cout << "c = " << c << "\n";
	cout << "x = " << x << "\n";
	cout << "y = " << y << "\n";
	cout << "z = " << z << "\n";
	cout << "::z = " << ::z << "\n\n"; // Access global z
	fn(c, x);
	cout << "Back inside main\n";
	cout << "The value of x is still " <<  x << "\n";
}
void fn(char c, long x){
	double y = 3.1459;
	++x;
	cout << "Inside fn\n";
	cout << "x = " << x << "\n";
	cout << "z = " << z << "\n";
	cout << "y = " << y << "\n\n";
	{
		char y = c;
		cout << "Inside block inside fn\n";
		cout << "y = " << y << "\n\n";
	}
	y/=3.00;
	cout << "Outside block inside fn\n";
	cout << "y = " << y << "\n";
	cout << "z++ = " << z++ << ", and ++z = " << ++z << "\n\n";
}


Output:

Inside main
c = a
x = 100
y = 6.2897
z = 3.145
::z = 25

Inside fn
x = 101
z = 25
y = 3.1459

Inside block inside fn
y = a

Outside block inside fn
y = 1.04863
z++ = 25, and ++z = 27

Back inside main
The value of x is still 100