class member functions with pointer parameters - class

Question

I have this homework assignment that is giving me a lot of trouble right now. My teacher is very vague in class and hard to communicate with. I will try very hard to articulate my thoughts here.
Here is the assignment:
(3pts) Given the following class header file, write the class’ source
code for each of the accessor and mutator functions listed. (Pay
attention to how the functions have listed their parameters, varying
between passing by reference and by value.) Don’t forget to comment
your code – it counts!
class Album {
private:
char * artist; // band or singer’s name
char * title; // title of the album
int year_released; // year the album is released
char * record_label; // name of company produced album
int num_songs; // number of songs on the album
int num_minutes_long; // length (mins) of album
char * genre; // genre of artist (eg, rock, pop, …)
public:
//constructors
Album();
Album(char *& a, char *& t);
//deconstructor
~Album();
//accessors and mutators
bool set_artist(char * a);
bool set_title(char * t);
bool set_year_released(int value);
bool set_record_label(char *& label);
bool set_num_songs(int value);
bool set_num_minutes_long(int value);
bool set_genre(char * g);
bool get_artist(char *& a);
bool get_title(char *& t);
int get_year_released();
bool get_record_label(char *& label);
int get_num_songs();
int get_num_minutes_long();
bool get_genre(char *& g);
};
Here is my work so far:
bool Album::set_artist(char * a)
{
*artist = a;
}
bool Album::set_title(char * t)
{
*title = t;
}
bool Album::set_year_released(int value)
{
year_released = value;
}
bool Album::set_record_label (char *& label)
{
*record_label = label;
}
bool Album::set_num_songs(int value)
{
num_songs = value;
}
bool Album::set_number_minutes_long(int value)
{
num_minutes_long = value;
}
bool Album::set_genre(char * g)
{
*genre = g;
}
bool Album::get_artist(char *& a)
{
return artist;
}
bool Album::get_title(char *& t)
{
return title;
}
int Album::get_year_released()
{
return year_released;
}
bool Album::get_record_label(char *& label)
{
return *record_label;
}
The input will be an array.
My questions:
First, am I on the right track?
When using (char * a) for a function, for example, this is passing the address of a, correct? so then *artist=a; changes what the address of a points to?
Also, the functions are bool when I would expect void. Why?
For all of the set_xxx functions, the parameter is *... but for set_record_label it is *&. That appears to be a mistake to me. Is that right?
What is the difference between *& and * as parameters?
Thank you for your time. I know there is a lot here.

Answer 1

First, am I on the right track?
A bit to general , let's go into details. But at least, you did not provide the required comments.
When using (char * a) for a function, for example, this is passing the address of a, correct?
No. It passes an address called a.
so then *artist=a; changes what the address of a points to?
This produces a type mismatch. artist is a pointer to char. *artist is the char variable artist points to. a is, agian, a pointer to char. So, you assign a pointer to a char variable => type mismatch.
Also, the functions are bool when I would expect void. Why?
I have no idea why do you expect void. However, bool makes sense: It allows the function to report, whether the operation (with side effect!) was successful or not.
For all of the set_xxx functions, the parameter is * ... but for
set_record_label it is *&. That appears to be a mistake to me. Is
that right?
Since your instructor stresses the use of different parameters, it is probably no error. However, in real life it would be a bad style.
What is the difference between *& and * as parameters?
* describes a pointer, & a reference. The referenced value can be a pointer again. I suggest that you reread the section on types in your textbook.