8.4. Pass-by-Reference with Pointers

There are three ways in C++ to pass arguments to a function—pass-by-value, pass-by-reference with reference arguments and pass-by-reference with pointer arguments. Chapter 6 compared and contrasted pass-by-value and pass-by-reference with reference arguments. In this section, we explain pass-by-reference with pointer arguments.

As we saw in Chapter 6, return can be used to return one value from a called function to a caller (or to simply return control). We also saw that arguments can be passed to a function using reference arguments. Such arguments enable the called function to modify the original values of the arguments in the caller. Reference arguments also enable programs to pass large data objects to a function and avoid the overhead of passing the objects by value (which, of course, requires making a copy of the object). Pointers, like references, also can be used to modify one or more variables in the caller or to pass pointers to large data objects to avoid the overhead of passing the objects by value.