From 33613a85afc4b1481367fbe92a17ee59c240250b Mon Sep 17 00:00:00 2001 From: Sven Eisenhauer Date: Fri, 10 Nov 2023 15:11:48 +0100 Subject: add new repo --- .../Prog1/examples/ch06/Fig06_21_23/Fig06_23.cpp | 53 +++++++++++++++++++++ Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.cpp | 55 ++++++++++++++++++++++ Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.h | 40 ++++++++++++++++ 3 files changed, 148 insertions(+) create mode 100644 Bachelor/Prog1/examples/ch06/Fig06_21_23/Fig06_23.cpp create mode 100644 Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.cpp create mode 100644 Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.h (limited to 'Bachelor/Prog1/examples/ch06/Fig06_21_23') diff --git a/Bachelor/Prog1/examples/ch06/Fig06_21_23/Fig06_23.cpp b/Bachelor/Prog1/examples/ch06/Fig06_21_23/Fig06_23.cpp new file mode 100644 index 0000000..a5b14b6 --- /dev/null +++ b/Bachelor/Prog1/examples/ch06/Fig06_21_23/Fig06_23.cpp @@ -0,0 +1,53 @@ +// Fig. 6.23: fig06_23.cpp +// Demonstrating a public member function that +// returns a reference to a private data member. +#include + +using std::cout; +using std::endl; + +// include definition of class Time from time4.h +#include "time4.h" + +int main() +{ + Time t; + + // store in hourRef the reference returned by badSetHour + int &hourRef = t.badSetHour( 20 ); + + cout << "Hour before modification: " << hourRef; + + // use hourRef to set invalid value in Time object t + hourRef = 30; + + cout << "\nHour after modification: " << t.getHour(); + + // Dangerous: Function call that returns + // a reference can be used as an lvalue! + t.badSetHour( 12 ) = 74; + + cout << "\n\n*********************************\n" + << "POOR PROGRAMMING PRACTICE!!!!!!!!\n" + << "badSetHour as an lvalue, Hour: " + << t.getHour() + << "\n*********************************" << endl; + + return 0; + +} // end main + +/************************************************************************** + * (C) Copyright 1992-2002 by Deitel & Associates, Inc. and Prentice * + * Hall. 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. * + *************************************************************************/ diff --git a/Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.cpp b/Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.cpp new file mode 100644 index 0000000..eef65f2 --- /dev/null +++ b/Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.cpp @@ -0,0 +1,55 @@ +// Fig. 6.22: time4.cpp +// Member-function definitions for Time class. + +// include definition of class Time from time4.h +#include "time4.h" + +// constructor function to initialize private data; +// calls member function setTime to set variables; +// default values are 0 (see class definition) +Time::Time( int hr, int min, int sec ) +{ + setTime( hr, min, sec ); + +} // end Time constructor + +// set values of hour, minute and second +void Time::setTime( int h, int m, int s ) +{ + hour = ( h >= 0 && h < 24 ) ? h : 0; + minute = ( m >= 0 && m < 60 ) ? m : 0; + second = ( s >= 0 && s < 60 ) ? s : 0; + +} // end function setTime + +// return hour value +int Time::getHour() +{ + return hour; + +} // end function getHour + +// POOR PROGRAMMING PRACTICE: +// Returning a reference to a private data member. +int &Time::badSetHour( int hh ) +{ + hour = ( hh >= 0 && hh < 24 ) ? hh : 0; + + return hour; // DANGEROUS reference return + +} // end function badSetHour + +/************************************************************************** + * (C) Copyright 1992-2002 by Deitel & Associates, Inc. and Prentice * + * Hall. 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. * + *************************************************************************/ diff --git a/Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.h b/Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.h new file mode 100644 index 0000000..92a5d84 --- /dev/null +++ b/Bachelor/Prog1/examples/ch06/Fig06_21_23/Time4.h @@ -0,0 +1,40 @@ +// Fig. 6.21: time4.h +// Declaration of class Time. +// Member functions defined in time4.cpp + +// prevent multiple inclusions of header file +#ifndef TIME4_H +#define TIME4_H + +class Time { + +public: + Time( int = 0, int = 0, int = 0 ); + void setTime( int, int, int ); + int getHour(); + + int &badSetHour( int ); // DANGEROUS reference return + +private: + int hour; + int minute; + int second; + +}; // end class Time + +#endif + +/************************************************************************** + * (C) Copyright 1992-2002 by Deitel & Associates, Inc. and Prentice * + * Hall. 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. * + *************************************************************************/ -- cgit v1.2.3