1   // Fig. 7.8: time6.h
2   // Cascading member function calls.
3   
4   // Declaration of class Time.
5   // Member functions defined in time6.cpp
6   #ifndef TIME6_H
7   #define TIME6_H
8   
9   class Time {
10  public:
11     Time( int = 0, int = 0, int = 0 );  // default constructor
12  
13     // set functions
14     Time &setTime( int, int, int ); // set hour, minute, second
15     Time &setHour( int );    // set hour
16     Time &setMinute( int );  // set minute
17     Time &setSecond( int );  // set second
18  
19     // get functions (normally declared const)
20     int getHour() const;     // return hour
21     int getMinute() const;   // return minute
22     int getSecond() const;   // return second
23  
24     // print functions (normally declared const)
25     void printMilitary() const;  // print military time
26     void printStandard() const;  // print standard time
27  private:
28     int hour;              // 0 - 23
29     int minute;            // 0 - 59
30     int second;            // 0 - 59
31  };
32  
33  #endif
34  // Fig. 7.8: time.cpp 
35  // Member function definitions for Time class.
36  #include "time6.h"
37  #include <iostream.h>
38  
39  // Constructor function to initialize private data.
40  // Calls member function setTime to set variables.
41  // Default values are 0 (see class definition).
42  Time::Time( int hr, int min, int sec ) 
43     { setTime( hr, min, sec ); }
44  
45  // Set the values of hour, minute, and second.
46  Time &Time::setTime( int h, int m, int s )
47  {
48     setHour( h );
49     setMinute( m );
50     setSecond( s ); 
51     return *this;   // enables cascading
52  }
53  
54  // Set the hour value
55  Time &Time::setHour( int h )
56  {
57     hour = ( h >= 0 && h < 24 ) ? h : 0;
58  
59     return *this;   // enables cascading
60  }
61  
62  // Set the minute value
63  Time &Time::setMinute( int m )
64  {
65     minute = ( m >= 0 && m < 60 ) ? m : 0;
66  
67     return *this;   // enables cascading
68  }
69  
70  // Set the second value
71  Time &Time::setSecond( int s )
72  {
73     second = ( s >= 0 && s < 60 ) ? s : 0;
74  
75     return *this;   // enables cascading
76  }
77  
78  // Get the hour value
79  int Time::getHour() const { return hour; }
80  
81  // Get the minute value
82  int Time::getMinute() const { return minute; }
83  
84  // Get the second value
85  int Time::getSecond() const { return second; }
86  
87  // Display military format time: HH:MM:SS
88  void Time::printMilitary() const
89  {
90     cout << ( hour < 10 ? "0" : "" ) << hour << ":"
91          << ( minute < 10 ? "0" : "" ) << minute;
92  }
93  
94  // Display standard format time: HH:MM:SS AM (or PM)
95  void Time::printStandard() const
96  {
97     cout << ( ( hour == 0 || hour == 12 ) ? 12 : hour % 12 ) 
98          << ":" << ( minute < 10 ? "0" : "" ) << minute 
99          << ":" << ( second < 10 ? "0" : "" ) << second
100         << ( hour < 12 ? " AM" : " PM" );
101 }
102 // Fig. 7.8: fig07_08.cpp
103 // Cascading member function calls together
104 // with the this pointer
105 #include <iostream.h>
106 #include "time6.h"
107 
108 int main()
109 {
110    Time t;
111 
112    t.setHour( 18 ).setMinute( 30 ).setSecond( 22 );
113    cout << "Military time: ";
114    t.printMilitary();
115    cout << "\nStandard time: ";
116    t.printStandard();
117 
118    cout << "\n\nNew standard time: ";
119    t.setTime( 20, 20, 20 ).printStandard();
120    cout << endl;
121 
122    return 0;
123 }