The rbegin() is a function in C++ STL. It returns a reverse iterator which points to the last element of the map. The reverse iterator iterates in reverse order and incrementing it means moving towards beginning of map.
r_i rbegin(); const_r_i rbegin() const;
It does not except any parameters.
Return Value: This method throws a reverse iterator to the reverse beginning of the sequence container.
Map contains following elements in reverse order e = 5 d = 4 c = 3 b = 2 a = 1