Java 使用字段对类的 Arraylist 进行排序

发布于04月08日

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;

}

考虑这些类

在另一节课上，我做了一个Book级的arraylist

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

推荐答案

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;
        });

在列表中.短(100)；b1是当前"书"的方式，b2是列表中的下一个"书"，返回值定义b1是在b2之前还是之后；

b1和b2是Book类型的变量，您可以更改它们的名称.

注意:字符串.compareTo()方法；按字母顺序排序，但优先考虑大写字母，例如:它将在小写字母"a"之前排序大写字母"Z".