C++ examples for Class:Constructor
Converts from Time24 to Time12 using constructor in Time12
#include <iostream> #include <string> using namespace std; class Time24//from w w w. j av a2s .c om { private: int hours; //0 to 23 int minutes; //0 to 59 int seconds; //0 to 59 public: //no-arg constructor Time24() : hours(0), minutes(0), seconds(0) { } Time24(int h, int m, int s) : //3-arg constructor hours(h), minutes(m), seconds(s) { } void display() const //format 23:15:01 { if(hours < 10) cout << '0'; cout << hours << ':'; if(minutes < 10) cout << '0'; cout << minutes << ':'; if(seconds < 10) cout << '0'; cout << seconds; } int getHrs() const { return hours; } int getMins() const { return minutes; } int getSecs() const { return seconds; } }; class Time12 { private: bool pm; //true = pm, false = am int hrs; //1 to 12 int mins; //0 to 59 public: //no-arg constructor Time12() : pm(true), hrs(0), mins(0) { } Time12(Time24); //1-arg constructor //3-arg constructor Time12(bool ap, int h, int m) : pm(ap), hrs(h), mins(m) { } void display() const { cout << hrs << ':'; if(mins < 10) cout << '0'; //extra zero for "01" cout << mins << ' '; string am_pm = pm ? "p.m." : "a.m."; cout << am_pm; } }; Time12::Time12( Time24 t24 ) //1-arg constructor { //converts Time24 to Time12 int hrs24 = t24.getHrs(); //get hours //find am/pm pm = t24.getHrs() < 12 ? false : true; mins = (t24.getSecs() < 30) ? //round secs t24.getMins() : t24.getMins()+1; if(mins == 60) //carry mins? { mins=0; ++hrs24; if(hrs24 == 12 || hrs24 == 24) //carry hrs? pm = (pm==true) ? false : true; //toggle am/pm } hrs = (hrs24 < 13) ? hrs24 : hrs24-12; //convert hrs if(hrs==0) //00 is 12 a.m. { hrs=12; pm=false; } } int main() { int h, m, s; while(true) { //get 24-hour time from user cout << "Enter 24-hour time: \n"; cout << " Hours (0 to 23): "; cin >> h; if(h > 23) //quit if hours > 23 return(1); cout << " Minutes: "; cin >> m; cout << " Seconds: "; cin >> s; Time24 t24(h, m, s); cout << "You entered: "; t24.display(); Time12 t12 = t24; //convert Time24 to Time12 cout << "\n12-hour time: "; t12.display(); cout << "\n\n"; } return 0; }