42 lines
1.9 KiB
C++
42 lines
1.9 KiB
C++
// fig09_18.cpp
|
|
// public member function that
|
|
// returns a reference to private data.
|
|
#include <iostream>
|
|
#include <fmt/format.h>
|
|
#include "Time.h" // include definition of class Time
|
|
|
|
int main() {
|
|
Time t{}; // create Time object
|
|
|
|
// initialize hourRef with the reference returned by badSetHour
|
|
int& hourRef{t.badSetHour(20)}; // 20 is a valid hour
|
|
|
|
std::cout << fmt::format(
|
|
"Valid hour before modification: {}\n", hourRef);
|
|
hourRef = 30; // use hourRef to set invalid value in Time object t
|
|
std::cout << fmt::format(
|
|
"Invalid hour after modification: {}\n\n", t.getHour());
|
|
|
|
// Dangerous: Function call that returns a reference can be
|
|
// used as an lvalue! POOR PROGRAMMING PRACTICE!!!!!!!!
|
|
t.badSetHour(12) = 74; // assign another invalid value to hour
|
|
|
|
std::cout << "After using t.badSetHour(12) as an lvalue, "
|
|
<< fmt::format("hour is: {}\n", t.getHour());
|
|
}
|
|
|
|
/**************************************************************************
|
|
* (C) Copyright 1992-2022 by Deitel & Associates, Inc. and *
|
|
* Pearson Education, Inc. All Rights Reserved. *
|
|
* *
|
|
* DISCLAIMER: The authors and publisher of this book have used their *
|
|
* best efforts in preparing the book. These efforts include the *
|
|
* development, research, and testing of the theories and programs *
|
|
* to determine their effectiveness. The authors and publisher make *
|
|
* no warranty of any kind, expressed or implied, with regard to these *
|
|
* programs or to the documentation contained in these books. The authors *
|
|
* and publisher shall not be liable in any event for incidental or *
|
|
* consequential damages in connection with, or arising out of, the *
|
|
* furnishing, performance, or use of these programs. *
|
|
**************************************************************************/
|