C Vector of pointers

Question

For my latest CS homework  I am required to create a class called Movie which holds title  director  year  rating  actors etc   Then  I am required to read a file which contains a list of this info and store it in a vector of pointers to Movies    I am not sure what the last line means  Does it mean  I read the file  create multiple Movie objects  Then make a vector of pointers where each element  pointer  points to one of those Movie objects   Do I just make two vectors - one of pointers and one of Movies and make a one-to-one mapping of the two vectors

User · Accepted Answer

It means something like this   std  vector lt Movie   gt  movies    Then you add to the vector as you read lines   movies push back new Movie          Remember to delete all of the Movie  objects once you are done with the vector

User · Answer

I am not sure what the last line means  Does it mean  I read the file  create multiple    Movie objects  Then make a vector of pointers where each element  pointer  points to one of those Movie objects    I would guess this is what is intended  The intent is probably that you read the data for one movie  allocate an object with new  fill the object in with the data  and then push the address of the data onto the vector  probably not the best design  but most likely what s intended anyway

User · Answer

As far as I understand  you create a Movie class   class Movie   private    std  string  title    std  string  director    int          year    int          rating    std  vector lt std  string gt  actors       and having such class  you create a vector instance   std  vector lt Movie  gt  movies    so  you can add any movie to your movies collection  Since you are creating a vector of pointers to movies  do not forget to free the resources allocated by your movie instances OR you could use some smart pointer to deallocate the movies automatically   std  vector lt shared ptr lt Movie gt  gt  movies

User · Answer

By dynamically allocating a Movie object with new Movie    you get a pointer to the new object  You do not need a second vector for the movies  just store the pointers and you can access them  Like Brian wrote  the vector would be defined as  std  vector lt Movie   gt  movies  But be aware that the vector will not delete your objects afterwards  which will result in a memory leak  It probably doesn t matter for your homework  but normally you should delete all pointers when you don t need them anymore

[c++] C++ Vector of pointers

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