how to output the book's title, author, and show the bookID seperately?-CodePudding

I'm a new java learner. Now I need to set the bookID from 1000, and according to the total number of input IDs, book author, and book title, respectively show the book's information. For example, when users enter 2, The Lord of the Rings; J. R. R. Tolkien; The Hunger Games; Suzanne Collins; The output is Book ID: 1000 Title: The Lord of the Rings Author: J. R. R. Tolkien Status: Available Book ID: 1001 Title: The Hunger Games Author: Suzanne Collins Status: Available.

I have completed part of the programming, but now I do not how to write the code in the BOOK[] array.

code:

import java.util.Scanner;

class Book{

    private Integer bookID = 1000;
    static Integer nextID;
    private String title;
    private String author;
    private boolean isBorrowed;
    
    public Book(String title, String author){
        this.title = title;
        this.author = author;
        this.isBorrowed = false;
        this.nextID = bookID  ;
    }
    
    public void borrowBook(){
        isBorrowed = true;
    }
    
    public void returnBook(){
        isBorrowed = false;
    }
    
    public boolean isBookBorrowed(){
        return isBorrowed;
    }
    
    public void show() {
        System.out.println("Book ID: "   bookID);
        System.out.println("Title: "   title);
        System.out.println("Author: "   author);
        System.out.print("Status: ");
        if (isBorrowed)
            System.out.println("Not Available");
        else
            System.out.println("Available");
        System.out.println();
    }
}

public class MyClass {

    public static void main(String args[]) {
       Scanner input=new Scanner(System.in);
       int num=input.nextInt();
       input.nextLine();
       
       Book[] books = new Book[num];
       String title;
       String author;
       for (int i=0; i<num; i  ) {
           books[i] =input.nextBook();
           title = input.nextLine();
           author = input.nextLine();
               
       }
    }
}

The following is my programming code, please help me see how to write the code of the array part, thank you very much!

CodePudding user response：

This is how it should be done:

nextId must be static because it's the one and only variable that has your last book id.

bookID should not be static because it's different for each book.

Book class:

class Book{
private static Integer nextID = 1000;
private Integer bookID;
private String title;
private String author;
private boolean isBorrowed;

public Book(String title, String author){
    this.title = title;
    this.author = author;
    this.isBorrowed = false;
    this.bookID  = nextID  ;
}

public void borrowBook(){
    isBorrowed = true;
}

public void returnBook(){
    isBorrowed = false;
}

public boolean isBookBorrowed(){
    return isBorrowed;
}

public void show() {
    System.out.println("Book ID: "   bookID);
    System.out.println("Title: "   title);
    System.out.println("Author: "   author);
    System.out.print("Status: ");
    if (isBorrowed)
        System.out.println("Not Available");
    else
        System.out.println("Available");
    System.out.println();
}
}

Main class:

import java.util.Scanner;

public class MyClass{
public static void main(String[] args) {

    Scanner input = new Scanner(System.in);
    int num = input.nextInt();
    input.nextLine();

    Book[] books = new Book[num];
    String title;
    String author;
    for (int i = 0; i < num; i  ) {
        title = input.nextLine();
        author = input.nextLine();
        books[i] = new Book(title,author);
    }
    for (int i = 0; i < num; i  ) {
        books[i].show();
    }
}
}

CodePudding user response：

The following code has a "database" of 2 books. The user is prompted to enter the book id as you stated, it starts with 1000. If the book is found they see your information via the show() method. If this isn't what you want let me know. OR if you want to add a feature that allows the user to input books we can do that too.. Please always give user prompts like "enter a number" when you use scanner. I went ahead and added so that the user can enter a book and immediately see that the book was stored with the correct id. its alternate main below


import java.util.Scanner;

public class Book {

        private static Integer nextID = 1000;
        private Integer bookID;
        private String title;
        private String author;
        private boolean isBorrowed;

        public Book(String title, String author){
            this.title = title;
            this.author = author;
            isBorrowed = false;
            bookID = nextID  ;
        }

        public void borrowBook(){
            isBorrowed = true;
        }

        public void returnBook(){
            isBorrowed = false;
        }

        public boolean isBookBorrowed(){
            return isBorrowed;
        }

        public void show() {
            System.out.println("Book ID: "   bookID);
            System.out.println("Title: "   title);
            System.out.println("Author: "   author);
            System.out.print("Status: ");
            if (isBorrowed)
                System.out.println("Not Available");
            else
                System.out.println("Available\n");

        }




        public static void main(String[] args) {
            // here we will create an array of 2 books as your data

            Book books[] = new Book[2];
            books[0] = new Book("blah", "blah bhal hald");
            books[1] = new Book("java", "girl power");


            Scanner input = new Scanner(System.in);
            System.out.println("Enter the book id:");
            int num = input.nextInt();
            for (int i = 0; i < books.length; i  ){
                if (books[i].bookID == num){
                    books[i].show();
                }
            }



        }
    }


alternate main:
  ```public static void main(String[] args) {
            // here we will allow the user to input book data and see the data
            // returned with the new id.
            Scanner input = new Scanner(System.in);
            System.out.println("Enter the number of books you wish to add:");
            int num = input.nextInt();
            input.nextLine();

            Book[] books = new Book[num];
            String title;
            String author;
            for (int i = 0; i < num; i  ) {
                System.out.println("enter the title:");
                title = input.nextLine();
                System.out.println("enter the author");
                author = input.nextLine();
                books[i] = new Book(title,author);
                System.out.println("The book you entered is:");
                books[i].show();
            }






        }