Overloading Increment ++ & Decrement --
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The increment (++) and decrement (--) operators are two important unary operators available in C++.
Following example explain how increment (++) operator can be overloaded for prefix as well as postfix usage. Similar way, you can overload operator (--).
Live Demo#include <iostream> using namespace std; class Time { private: int hours; // 0 to 23 int minutes; // 0 to 59 public: // required constructors Time() { hours = 0; minutes = 0; } Time(int h, int m) { hours = h; minutes = m; } // method to display time void displayTime() { cout << "H: " << hours << " M:" << minutes <<endl; } // overloaded prefix ++ operator Time operator++ () { ++minutes; // increment this object if(minutes >= 60) { ++hours; minutes -= 60; } return Time(hours, minutes); } // overloaded postfix ++ operator Time operator++( int ) { // save the orignal value Time T(hours, minutes); // increment this object ++minutes; if(minutes >= 60) { ++hours; minutes -= 60; } // return old original value return T; } }; int main() { Time T1(11, 59), T2(10,40); ++T1; // increment T1 T1.displayTime(); // display T1 ++T1; // increment T1 again T1.displayTime(); // display T1 T2++; // increment T2 T2.displayTime(); // display T2 T2++; // increment T2 again T2.displayTime(); // display T2 return 0; }
When the above code is compiled and executed, it produces the following result −
H: 12 M:0 H: 12 M:1 H: 10 M:41 H: 10 M:42
cpp_overloading.htm
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