Exercise 101: The library printBooks()

[Alberto]

Hi,

I'm having problems with week 6 exercise 101.2 on course OOP part 1.

When I iterate over the array items (created in the Library class, holding all the Book objects) I get an empty output. I thought that by calling the toString() method, implemented in the Book class, I would easily get to print all the info of all the books stored in the array.
If I instead use "sout" I get the expected output.
What am I missing?

public void printBooks(){
       
        for (Book obj : this.items){
            obj.toString(); //this works instead: System.out.println(obj);
        }
       
    }

Best regards,

Alberto