(以下是完整代码) 我刚刚为课堂提交了一个实验,我们必须制作一个描述某本书的类。我无法弄清楚如何做到两件事。 1. 如果有人为“页数”或“建议零售价”输入小于零的值,则该值必须设置为零。在此代码中,即使该值为正,该值也被设置为0。在:
if ( pages <= 0 )
{
pages = 0;
}
如果我将第二个“0”设置为其他数字,例如:
if ( pages <= 0 )
{
pages = 1;
}
那么您输入的“页面”所对应的值将为1。但是,只有在您输入的值为负数时,它才应该为1。我不知道我错在哪里。
第二件我解决不了的事情是,在代码底部,我们需要显示所有信息。我的老师要求我们将书籍是否为平装显示为“是”或“否”,而不是“true”或“false”。我该怎么做?我尝试添加一个if / else语句像这样:
System.out.println(“平装:”+ if(paperback = true){Yes} if(paperback = false){no};)
没有奏效,我无法解决。下面是整个代码
public class Book {
// Instance variables
private String title;
private String author;
private int isbn;
private int pages;
private boolean paperback;
private int suggestedRetailPrice;
/**
* Default contructor
*/
public Book() {
title = "";
author = "";
isbn = 0;
pages = 0;
paperback = false;
suggestedRetailPrice = 0;
}
/**
* book information
*/
public Book(String whatIsTitle, String whoIsAuthor, int isbnCode,
int numberOfPages, boolean isItPaperback,
int theSuggestedRetailPrice) {
title = whatIsTitle;
author = whoIsAuthor;
isbn = isbnCode;
if (pages <= 0) {
pages = 0;
} else {
pages = numberOfPages;
}
paperback = isItPaperback;
if (suggestedRetailPrice <= 0) {
suggestedRetailPrice = 0;
} else {
suggestedRetailPrice = theSuggestedRetailPrice;
}
}
/**
* @return title
*/
public String getTitle() {
return title;
}
/**
* @return author
*/
public String getAuthor() {
return author;
}
/**
* @return isbn
*/
public int getIsbn() {
return isbn;
}
/**
* @return pages
*/
public int getPages() {
return pages;
}
/**
* @return paperback
*/
public boolean getPaperback() {
return paperback;
}
/**
* @return suggestedRetailPrice
*/
public int getSuggestedRetailPrice() {
return suggestedRetailPrice;
}
/**
* title
*/
public void setTitle(String whatIsTitle) {
title = whatIsTitle;
}
/**
* author
*/
public void setAuthor(String whoIsAuthor) {
author = whoIsAuthor;
}
/**
* isbn code
*/
public void setIsbn(int isbnCode) {
isbn = isbnCode;
}
/**
* number of pages
*/
public void setPages(int numberOfPages) {
if (pages <= 0) {
pages = 0;
} else {
pages = numberOfPages;
}
}
/**
* is it paperback
*/
public void setPaperback(boolean isItPaperback) {
paperback = isItPaperback;
}
/**
* suggested retail price
*/
public void setSuggestedRetailPrice(int theSuggestedRetailPrice) {
if (suggestedRetailPrice <= 0) {
suggestedRetailPrice = 0;
} else {
suggestedRetailPrice = theSuggestedRetailPrice;
}
}
/**
* displays information
*/
public void displayBook() {
System.out.println("Title : " + title);
System.out.println("Author : " + author);
System.out.println("ISBN : " + isbn);
System.out.println("Pages : " + pages);
System.out.println("Paperback : " + paperback);
System.out.println("Suggested price : " + suggestedRetailPrice);
}
}