返回 true 或 false 方法

Question

public class Book { 
String title; 
boolean borrowed; 
// Creates a new Book 
public Book(String bookTitle){ 
    bookTitle= "The Da Vinci Code";
} 
// Marks the book as rented 
public void borrowed() { 
    int borrowed= 1;
    // Implement this method 
} 
// Marks the book as not rented 
public void returned() { 
    int returned = 2;
    // Implement this method 
} 
// Returns true if the book is rented, false otherwise 
public boolean isBorrowed(int returned, int borrowed) { 
    if (borrowed < 2 )
    return true;
    else 
    return false;
    // Implement this method 
} 
// Returns the title of the book 
public String getTitle() { 
    String bookTitle= "The Da Vinci Code";
    return bookTitle;
    // Implement this method 
}
public static void main(String[] arguments){ 
    // Small test of the Book class
    int returned= 1;
    int borrowed= 2;
    Book example = new Book("The Da Vinci Code"); 
    System.out.println("Title (should be The Da Vinci Code): " +example.getTitle()); 
    System.out.println("Borrowed? (should be false): " + example.isBorrowed(returned, borrowed)); 
    example.borrowed(); 
    System.out.println("Borrowed? (should be true): " + example.isBorrowed(returned, borrowed)); // should be returning true but it not. It printing false
    example.returned(); 
    System.out.println("Borrowed? (should be false): " + example.isBorrowed(returned, borrowed)); 
} 

我正在做课程和方法。我正在上一本书课，它几乎可以工作，但我需要让第二个打印语句打印为真，但我得到了假。我应该怎么做才能解决这个问题？

Answer 1

您正在借用 void 中创建一个新的 int，它与 main 方法中的 int 不同，因此使其成为借用的类 int 的属性，不要声明它两次。

Answer 2

在 main() 方法中将局部变量 borrowed 设置为 2。您调用isBorrowed()并向其传递此变量。然后在isBorrowed()中，您说如果borrowed小于 2，则返回 true。不是这样你返回假的。

borrowed()方法需要将Book中的borrowed字段设置为 true，而不是设置局部变量。

您应该了解声明变量和为变量赋值之间的区别