我已经在我的类“BookList”中构建了一个数组列表,但我需要它在另一个类中打印。
我想我可能必须将 Arraylist 的打印变成一个方法,这样就可以从不同的类调用它;如果我错了,我还能做些什么来实现这一目标?
下面是我的代码,供引用。
import java.util.ArrayList;
public class BookList {
public static void main (String[] args){
Book a = new Book();
a.setTitle("Random ");
a.setAuthor("Craig Robertson");
a.setBookID("1847398812");
a.setonLoan(false);
a.setNumberofLoans(3);
Book b = new Book();
b.setTitle("The Last Refuge");
b.setAuthor("Craig Robertson");
b.setBookID("1471127753");
b.setonLoan(false);
b.setNumberofLoans(2);
Book c = new Book();
c.setTitle("The Bird That Did Not Sing");
c.setAuthor("Alex Gray");
c.setBookID("0751548278");
c.setonLoan(true);
c.setNumberofLoans(7);
ArrayList<Book> BookList = new ArrayList<Book>();
BookList.add(a);
BookList.add(b);
BookList.add(c);
int count = BookList.size();
System.out.println("Count: " + count);
System.out.println("");
for (Book d : BookList){
System.out.println(d);
}
}
}
为此,我的“Book”类中有 toString() 方法,这样我就可以打印所有对象。
另一个问题:如何仅打印每个对象的标题和作者?
最佳答案
在 Book
类中创建一个静态方法来处理显示:
public static void showBooks(ArrayList<Book> books) {
for (Book d : Books){
System.out.println(d); // calls the 'toString' method on each Book object
}
并从主方法中这样调用它:
ArrayList<Book> BookList = new ArrayList<Book>();
BookList.add(a);
BookList.add(b);
BookList.add(c);
Book.showBooks(BookList); // prints the books, one by one
How would I print just the title and author of each object?
您可以选择仅在 的 overriden
类:toString
方法中打印 title
和 author
>图书
@Override
public String toString() {
// 'author' & 'title' are members of the 'Book' class
return "Author: " + author + "- Title: " + title;
}
关于java - 创建一个打印 ArrayList 的方法,然后在另一个类中调用它,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34192644/