asked on

Debugg

The following two functions are virtually identical. One searches the database by id and the other by name. The search by id (findStudent) works fine and has been tested. The search by name(searchStudent) has crashed every way I have set it up. That is, using a while loop or for loop hasn't made a difference. The for loop should work even if it is undesirable by some... Could the spaces that precede the name field on a typical entry (i.e. 123456, John, 35, 3.4, Born in Boston... screw up the search function?

Student *Database::searchStudent(char *name)
{
      if(!name) {cout<<"Bad entry!"; return 0;}            // nothing to delete
      if(!_head)                                                                  // no list
            { cout << "Empty list!";
              return 0;
            }

      for (Student *p = _head; p!= 0 && strcmp(p->_name,name)!= 0; p = p -> _next); // classic traverse of list
            if(strcmp(p->_name,name)== 0)
                  {
                   cout<<"Found name:\n";
                   print(p);
                  }

            else
                  if(p == 0)
            cout <<"Name not found!\n";
            return 0;
}

Student *Database::findStudent(long ID)
{
      if(!ID) {cout<<"Bad entry!"; return 0;}            // nothing to delete
      if(!_head)                                                                  // no list
            { cout << "Empty list!";
              return 0;
            }

      for (Student *p = _head; p!= 0 && p->_id != ID; p = p -> _next); // classic traverse of list
            if(p ->_id == ID)
                  {
                   cout<<"Found ID:\n";
                   print(p);
                  }

            else
                  if(p == 0)
            cout <<"ID not found!\n";
            return 0;
}

the following are the class definitions
class Student{
      public:
            Student(){_next = _prev = 0; _born = _name = _note = 0;}
            Student(char *buff);
            ~Student();
            print();
            friend class Database;

      private:
            long _id;
            char *_name;
            int _age;
            float _cum;
            char *_born;
            char *_note;
            Student *_prev;
            Student *_next;
};

class Database{
      public:

            void init();
            void print(Student *p);
            void printNames();
            void printAges(int A);
            void readDatabase();
            void writeDatabase();
            void addStudent(Student *pNew);
            int delStudent(long ID);
            Student *findStudent (long ID);
            Student *searchStudent (char *name);
            Database(){_head=0,_numStudents=0;}
            ~Database(){init();}

       private:
            Student *_head;
            int _numStudents;

};
the following is the driver program within main:

case 's':
                  case 'S': // Search a student
                  {
                        char buff[25];

                        printf("\nEnter student Name:\n\n");
                        cin >>buff;
                              database1.searchStudent(buff);
                  }break;
Also, string.h has been included for the strcmp func.
Thanks much for the help!!