class Book
{
    // The fields.
    private String author;
    private String title;
    private int pages;
    private String refNumber;
    private int borrowed;

    
    public Book(String bookAuthor, String bookTitle, int bookPages)
    {
        author = bookAuthor;
        title = bookTitle;
        pages = bookPages;
        refNumber = "";
        borrowed = 0;
    }

    public String getAuthor() {
        return author;
    }
    
    public String getTitle() {
        return title;
    }
    
    public int getPages() {
        return pages;
    }
    
    public void printAuthor() {
        System.out.println("Forfatter: " + author + ".");
    }
    
    public void printTitle() {
        System.out.println("Titel: " + title + ".");
    }
    
    public void printPages() {
        System.out.println("Antal sider: " + pages + ".");
    }
    
    public void printRefNumber() {
        if(refNumber.length() < 1) {
            System.out.println("Ref.nr.: ZZZ.");
        }    
        else {
            System.out.println("Ref.nr.: " + refNumber + ".");
        }
    }
    
    public void printBorrowed() {
        System.out.println("Bogen har været udlånt " + borrowed + " gange.");
    }
        
        
    public void printDetails() {
        printTitle();
        printAuthor();
        printPages();
        printRefNumber();
        printBorrowed();
    }
    
    public void setRefNumber(String ref) {
        if(ref.length() >= 3){
        refNumber = ref;}
        
        else{
        System.out.println("Fejl: Ref.nummeret er for kort.");}
    }
    
    public String getRefNumber() { 
        return refNumber;
    }
    
    public void setBorrowed() {
        borrowed = borrowed + 1;
    }
    
    public int getBorrowed() {
        return borrowed;
    }
    
    
}