我試圖運行一個程序,如果一切順利,能夠花一年時間並返回當年發佈的專輯的標題。我已經給了它6張專輯,現在我正在試圖打印一個標題。我修復了一些令人沮喪的錯誤,但這是我以前從未見過的錯誤。錯誤出現在第21行,但我不確定它的含義。誰能幫忙?「線程中的異常」main「java.lang.NullPointerException」
package songselector;
import java.util.Scanner;
public class Main {
public class Album
{
int year; String title;
public Album() {
this.year = 0; this.title = null;
}
public Album (int year, String title) {
this.year = year; this.title = title;
}
}
class CAKE {
Album[] albums;
public CAKE() {
albums = new Album[6];
albums[0].year = 1994; albums[0].title = "Motorcade Of Generosity";
albums[1].year = 1996; albums[1].title = "Fashion Nugget";
albums[2].year = 1998; albums[2].title = "Prolonging The Magic";
albums[3].year = 2001; albums[3].title = "Comfort Eagle";
albums[4].year = 2004; albums[4].title = "Pressure Chief";
albums[5].year = 2011; albums[5].title = "Showroom of Compassion";
}
public void printAlbum (int y) {
System.out.println (albums[y].title);
}
}
public static void main(String[] args) {
new Main().new CAKE().printAlbum (0);
}
}
它是'專輯[0]',並且使用他的ctor它可以是'albums [0] =新專輯(1994,「Motorcade Of Generosity」);' – entonio 2011-05-11 00:53:43
oops ...將編輯。謝謝! – MByD 2011-05-11 00:54:49
啊,好吧。謝謝你,這很有道理。現在運行良好。 – James 2011-05-11 01:00:52