Updating vector of class objects using push_back in various functions

Question

I have a vector of class objects I\'ve created in main by reading in a data file. I\'m then passing around the vector to several different files containing functions that p

Answer 1

You should pass the vector by reference to modify the original global vector.

void addBook(vector& books)
                            ^^^

Otherwise you are passing a copy of the original vector to the function and modifying that not the global version.