Call by reference:
Arguments to a function can be passed in two way; one by call by value and other by call
by reference. Call by value is passed either through a constant or variable. The call by reference is passed through address operator (&). In C the function definition argument must be declared as pointer variable to pass by reference, where as in C++ the call by reference can be used without declaring the function arguments as pointer variables. But in C++ both pointer argument method and without pointer argument can be adopted.
void f_ref(int &a, int &b); // void f_ref(int, int) is wrong for reference variable;
void main( )
{int a, b;
f_ref(a, b); // The value a is 10 and b is 20.
}
void f_ref(int &x, int &y)
{x =10;
y=20;