3.java定义一个能输出书名、作者、出版社和价格等信息的图书类，存放于包net.book下。然后再编写一个存放于包com.test下的测试类，类中定义一个一维图书对象数组，用于存放6本图书，然后使用增强for语句显示所有的图书信息。用三种简单方法

方法一：

net.book.Book类代码：

package net.book;

public class Book {
    private String title;
    private String author;
    private String publisher;
    private double price;

    public Book(String title, String author, String publisher, double price) {
        this.title = title;
        this.author = author;
        this.publisher = publisher;
        this.price = price;
    }

    public String getTitle() {
        return title;
    }

    public String getAuthor() {
        return author;
    }

    public String getPublisher() {
        return publisher;
    }

    public double getPrice() {
        return price;
    }

    @Override
    public String toString() {
        return "Book{" +
                "title='" + title + '\'' +
                ", author='" + author + '\'' +
                ", publisher='" + publisher + '\'' +
                ", price=" + price +
                '}';
    }
}

com.test.Test类代码：

package com.test;

import net.book.Book;

public class Test {
    public static void main(String[] args) {
        Book[] books = new Book[6];
        books[0] = new Book("Java编程思想", "Bruce Eckel", "机械工业出版社", 89.00);
        books[1] = new Book("深入浅出设计模式", "程杰", "电子工业出版社", 49.00);
        books[2] = new Book("Effective Java", "Joshua Bloch", "机械工业出版社", 79.00);
        books[3] = new Book("Java核心技术-卷1", "Cay S. Horstmann", "机械工业出版社", 109.00);
        books[4] = new Book("Java 8实战", "Raoul-Gabriel Urma", "人民邮电出版社", 89.00);
        books[5] = new Book("Head First设计模式", "Eric Freeman", "中国电力出版社", 69.00);

        // 方法一：使用普通for循环遍历
        for (int i = 0; i < books.length; i++) {
            System.out.println(books[i]);
        }
    }
}

方法二：

com.test.Test类代码：

package com.test;

import net.book.Book;

public class Test {
    public static void main(String[] args) {
        Book[] books = new Book[6];
        books[0] = new Book("Java编程思想", "Bruce Eckel", "机械工业出版社", 89.00);
        books[1] = new Book("深入浅出设计模式", "程杰", "电子工业出版社", 49.00);
        books[2] = new Book("Effective Java", "Joshua Bloch", "机械工业出版社", 79.00);
        books[3] = new Book("Java核心技术-卷1", "Cay S. Horstmann", "机械工业出版社", 109.00);
        books[4] = new Book("Java 8实战", "Raoul-Gabriel Urma", "人民邮电出版社", 89.00);
        books[5] = new Book("Head First设计模式", "Eric Freeman", "中国电力出版社", 69.00);

        // 方法二：使用增强for循环遍历
        for (Book book : books) {
            System.out.println(book);
        }
    }
}

方法三：

com.test.Test类代码：

package com.test;

import net.book.Book;

public class Test {
    public static void main(String[] args) {
        Book[] books = new Book[6];
        books[0] = new Book("Java编程思想", "Bruce Eckel", "机械工业出版社", 89.00);
        books[1] = new Book("深入浅出设计模式", "程杰", "电子工业出版社", 49.00);
        books[2] = new Book("Effective Java", "Joshua Bloch", "机械工业出版社", 79.00);
        books[3] = new Book("Java核心技术-卷1", "Cay S. Horstmann", "机械工业出版社", 109.00);
        books[4] = new Book("Java 8实战", "Raoul-Gabriel Urma", "人民邮电出版社", 89.00);
        books[5] = new Book("Head First设计模式", "Eric Freeman", "中国电力出版社", 69.00);

        // 方法三：使用Lambda表达式遍历
        java.util.Arrays.stream(books).forEach(System.out::println);
    }
}