Sorting a Arraylist of class with fields-CodePudding

public class Publication {
private String name;
private String author;
private int price;
private String language;}
public class Book extends Publication {
private int ISBN;

public Book(String name, String author, String language, int price, int ISBN) {
    super(name, author, language, price);
    this.ISBN = ISBN;

}

public class Book extends Publication {
private int ISBN;

public Book(String name, String author, String language, int price, int ISBN) {
    super(name, author, language, price);
    this.ISBN = ISBN;

}

consider these classes

In another class I made an arraylist of Book class

now I want to sort and print this arraylist based on name and then author
but I don't know what can I do

CodePudding user response：

List<Book> books = new ArrayList<>();

        //put elements in your list

        books.sort((b1,b2) ->{
            int comparator;
            if (b1.name==b2.name){
                comparator = b1.author.compareTo(b2.author);
            } else {
                comparator = b1.name.compareTo(b2.name);
            }
            return comparator;
        });

in list.short((b1,b2)); is how b1 is the current "Book", and b2 is the next "Book" in the list, the return value defines whether b1 is before or after b2;

b1 and b2 are variables of type Book, you can change their name.

note: the String.compareTo() method; sorts alphabetically, but prioritizes uppercase letters, example: it will sort uppercase "Z" before lowercase "a".