C++ / Best practice to work with pointers

Question

I finished a beginner course on udemy, but I always struggle with understanding pointers, I started many times and pointers crashed my curiosity for programming every time. Now I finally want to pass this border. The point of this question, while the instructor was creating a pointer of an object he allocated them like described here:

person* k = new person[3] ;

for (i=0;i<3;i++){
// Why did he create a new person and copy the object from a pointer? 
// isn't this wastage of space or has it a good reason.
    person a_person = k[i] ;
    char *name = "Superman" ;
    a_person.set_name(name, strlen(name)) ;
    a_person.set_age(30) ;
    a_person.describe() ;

// isn't this better? Directly using the pointer to access the memory
// our pointer is pointing and change the variables there?
    char *surname = "Spiderman" ;
    (k+i)->set_name(surname, strlen(name)) ;
    (k+i)->set_age(10) ;
    (k+i)->describe();

}

class person {

public:
    person();
    ~person();
    int length() ;
    void get_addresses();
    int getid() ;
    void set_name(char *ptr_name, size_t bytes) ;
    char* get_name() ;
    int get_age() ;
    void describe() ;
    void set_age(int number) ;

private:
    char* name ;
    int age ;
    int id ;
    size_t bytes = 30 ;
    int get_unique() ;
    int setid() ;
};

E: The course had other code, but somehow I have to try it, so I built this person class with some functions and char*.

E2: yes, in the advanced c++ are all these structures, vectors, lists, maps and many c++11 features mentioned

Answer 1

In first case you r creating a new object and copying data from object in array. In such way you r working with 'a_person' object, not with object in array. In second case you are working with objects in array.

Answer 2

• Remember to manage the ownership of your pointer carefully. Pair your new with delete , and new[] with delete[] , or you may leak the resource.

• Let smart pointer to help you to manage the ownership of pointer, check std::unique_ptr or std::shared_ptr .

• Use const char* to hold literal string and so does in parameter type instead of char* .

• That k[i] returned is an object, not pointer. k is initialized as an array of person in length 3. k[i] means to dereference the element of array at i position. I guess the instructor lost a & to bind the k[i] like person& a_person = k[i];

• Try other learning resource.