CODEWITHSUNDEEP
c++
Alpha
Alpha

Reputation: 77

Changed value through set function but; value not changing when called

I have two classes an "Author" and a "Book" class. The book class constructor uses the Author constructor. The problem that is happening is that when I change a value in the author class using a setter function and then I try using the Book print function to print all the information, the new value is not printed.

I set the default constructor of Author to implement all private value.

//Author class

Author::Author(string name, string email, char gender)
{
    this->name = name;
    this->email = email;
    this->gender = gender;
}
Author::Author()
{
}

Author::~Author()
{
}
string Author::getEmail()
{
    return email;
}

void Author::setEmail(string email)
{
    this->email = email;
}
string Author::print()
{
    return name + " (" + gender + ") @ " + this->email;
}

//Book class

Book::Book(string name, Author author, double price)
{
    this->author = author;
    this->name = name;
    this->price = price;
}
Book::Book()
{
}

Book::~Book()
{
}
Author Book::getAuthor()
{
    return this->author;
}
string Book::print()
{
    return name + " by " + this->author.print(); 
}

//Main class

int main()
{
    Author author("Jonathan Gonzalez", "g.jonathan.com",'M');
    Book stock("NO BS! THE REALITY OF THE STOCK MARKET", author, 4.99);
    cout << author.print() << "\n" << endl;
    cout << stock.print() << "\n" << endl;

    author.setEmail("[email protected]");
    stock.setPrice(2.99);
    cout << stock.print() << "\n" << endl;
    return 0;
}

When I use the stock.print() function after I have changed a value using the author.setEmail() function it does not print using the new email.

OUTPUT Jonathan Gonzalez (M) @ g.jonathan.com

NO BS! THE REALITY OF THE STOCK MARKET by Jonathan Gonzalez (M) @ g.jonathan.com

NO BS! THE REALITY OF THE STOCK MARKET by Jonathan Gonzalez (M) @ g.jonathan.com

// //Expected OUTPUT

Jonathan Gonzalez (M) @ g.jonathan.com

NO BS! THE REALITY OF THE STOCK MARKET by Jonathan Gonzalez (M) @ g.jonathan.com

NO BS! THE REALITY OF THE STOCK MARKET by Jonathan Gonzalez (M) @ [email protected]

Upvotes: 1

Views: 63

Answers (2)

R Sahu
R Sahu

Reputation: 206567

When I use the stock.print() function after I have changed a value using the author.setEmail() function it does not print using the new email.

That's because stock has its own copy of the Author object. Changing the state of the author object in main does not change the state of stock.author, the Author object in stock.

I would recommend adding a member function to Book to set the Author.

void Book::setAuthor(Author const& author)
{
    return this->author = author;
}

In main, call the function.

author.setEmail("[email protected]");
stock.setAuthor(author);  // Add this
stock.setPrice(2.99);

Now, the call to print will work as per your expectation.

cout << stock.print() << "\n" << endl;

Upvotes: 3

shingo
shingo

Reputation: 27011

You should make Author inside Book class as a pointer.

class Book
{
    Author* author;

    Book(string name, Author* author, double price)
    {
        this->author = author;
    }
}

Then pass the address

Book stock("...", &author, 4.99);

Upvotes: 0

Related Questions