Question

JAVA题：编写一个Book类用于描述图书，要求如下：

Answer 1

public class Book {

private String title ;
private String author;
private int sell;

public Book(){

}

public Book(String title,String author,int sell){

this.title=title;
this.author=author;
this.sell=sell;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getAuthor() {
return author;
}
public void setAuthor(String author) {
this.author = author;
}
public int getSell() {
return sell;
}
public void setSell(int sell) {
this.sell = sell;
}

public String toString() {
return "D [title=" + title + ", author=" + author + ", sell=" + sell
+ "]";
}

}

追问

"D [title=" + title + ", author=" + author + ", sell=" + sell
+ "]"
为什么D后面加的是中括号"[ ]',而不是小括号"( )"？

追答

toString()我改一下吧；
public String toString() {
return author+"著"+title+"售出"+sell+"本"
其实无论是中括号或者圆括号（）都是无所谓的 因为只是一个字符串而已

这样就会显示 张三著gama语言售出100本 前提是author是张三 title是gama语言 sell是100