9.4 Summary of Parameter Types

Table 9-2 lists the various parameter types.

Table 9-2. Parameter types

Type	Declaration
Call by value	function(int var) Value is passed into the function and can be changed inside the function, but the changes are not passed to the caller.
Constant call by value	function(const int var) Value is passed into the function and cannot be changed.
Reference	function(int& var) Reference is passed to the function. Any changes made to the parameter are reflected in the caller.
Constant reference	function(const int& var) Value cannot be changed in the function. This form of parameter is more efficient than "constant call by value" for complex data types. (See Chapter 12.)
Array	function(int array[]) Value is passed in and may be modified. C++ automatically turns arrays into reference parameters.
Call by address	function(int *var) Passes a pointer to an item. Pointers are covered in Chapter 15.