#include <iostream>
using std::cout;
  using std::endl;

int sqrByValue(int);
void sqrByPointer(int *);
void sqrByRef(int &);

int main()
{
   int x = 2, y = 3, z = 4;

   cout << "x = " << x << " before sqrByVal\n"
        << "Value returned by sqrByVal: "
        << sqrByValue(x)
        << "\nx = " << x << " after sqrByVal\n\n";
   cout << "y = " << y << " before sqrByPointer\n";
   sqrByPointer(&y);
   cout << "y = " << y << " after sqrByPointer\n\n";
 
     cout << "z = " << z << " before sqrByRef\n";
   sqrByRef(z);
   cout << "z = " << z << " after sqrByRef\n";

   return 0;
}
int sqrByValue(int a)
{
   return a *= a;   
		// caller's argument not modified
}

void sqrByPointer(int *bPtr)
{
   *bPtr *= *bPtr;  
		// caller's argument modified
}

void sqrByRef(int &cRef)
{
   cRef *= cRef;    
		// caller's argument modified
}