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