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)); 
}

我正在上课和方法。我正在制作一本书课，它几乎可以工作但是我需要让第二个印刷语句打印出来，但我得到的是假的。我该怎么做才能解决这个问题？

Answer 1

你在void中使用了一个新的int，并且它与main方法中的int不同，所以把它作为int类的一个属性，不要声明它两次。

Answer 2

您在borrowed方法中将局部变量main()设置为2。您调用isBorrowed()并将此变量传递给它。然后在isBorrowed()中，如果borrowed小于2，则表示返回true。不是这样，你返回false。

您的borrowed()方法需要将borrowed中的Book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将值分配给变量

之间的区别

返回一个真或假的方法

2 个答案: