what is call by reference?

Call by reference: the formal parameters must be of type reference. When we pass parameters by reference the formal parameters become like and alias variable to the formal parameters. To pass arguments by reference, the function call is similar to that of Call by value. In the function declarator the formal parameters are preceded by the '&' operator. It is possible to return more than one value from a function to the main program.

Any changes to the formal parameters are automatically reflected back to the actual parameters in the main program. Using this method know duplicate set of variables are created.

call by reference?