C++ iterator as class member used in class method -

i have following code.

the for-loop @ end should go through object of ccarlist class, print out the a_rz , vin of car structure , stop when atend() method returns true.

but doesnt stop , when try reach values of a_rz , vin gives segmentation fault.

could someone, please, explain how use iterator in ccarlist class?

thanks

    typedef struct car {          string a_rz;         unsigned int vin;     }car;      class ccarlist      {        public:         string         rz           ( void ) const;         unsigned int   vin          ( void ) const;         bool           atend        ( void ) const;         void           next         ( void );          vector<car*> vcar;         vector<car*>::const_iterator = vcar.begin();        public:                        ccarlist     ( void ){}                        ~ccarlist    ( void ){}      };       string ccarlist::rz ( void ) const {         return "ahoj"; //(**it).a_rz;      }     unsigned int ccarlist::vin ( void ) const{         return 5; //(**it).vin;     }     bool ccarlist::atend ( void ) const {          if(it == vcar.end()) return true;         return false;     }     void  ccarlist::next ( void ){         it++;     }      int main() {       car  *a, *b, *c;     = new car;     b = new car;     c = new car;      (*a).a_rz = "abc";     (*a).vin = 45;     (*b).a_rz = "dfg";     (*b).vin = 65;     (*c).a_rz = "jkl";     (*c).vin = 23;      ccarlist list_of_cars;     list_of_cars.vcar.push_back(a);     list_of_cars.vcar.push_back(b);     list_of_cars.vcar.push_back(c);      ( ; ! list_of_cars . atend (); list_of_cars . next () )          cout << list_of_cars . rz () << ", " << list_of_cars . vin () << endl;       return 0;     } 

your problem iterator it not being updated/invalidated after each push_back. after last insertion still points "nothing" beginning.

soultion simple -- update iterator. add method adding new elements:

void ccarlist::add(car* car)  {     vcar.push_back(car);     = vcar.begin(); } 

and just:

list_of_cars.add(a); list_of_cars.add(b); list_of_cars.add(c); 

also regarding above problem, you're trying wrap vector , provide same functionality vectoralready provides. consider moving functionality related car structure inside structure. , leaving in ccarlist methods related ccarlist. short piece of code show mean:

typedef struct car {     string a_rz;     unsigned int vin; } car;  class ccarlist { public:     vector<car*> vcar;     ccarlist(void){}     ~ccarlist(void){} };  int main() {      car  *a, *b, *c;     = new car;     b = new car;     c = new car;      a->a_rz = "abc";     a->vin = 45;     b->a_rz = "dfg";     a->vin = 65;     c->a_rz = "jkl";     c->vin = 23;      ccarlist list_of_cars;      list_of_cars.vcar.push_back(a);     list_of_cars.vcar.push_back(b);     list_of_cars.vcar.push_back(c);      for(auto car : list_of_cars.vcar)         cout << car->a_rz << ", " << car->vin << endl;      return 0; }