java - 我的2D数组Java代码找不到错误

Question

Java说存在预期的“]”错误。我找不到我的代码有什么问题吗？ Song类是另一个类组合类，因此没有问题。在此先感谢您的帮助

public class Jukebox
{
    Song[][] songList;

    songList[0][0] = new Song("Jet Airliner", 5 );

    songList[0][1] = new Song( "Slide", 4 );

    songList[0][2] = new Song( "Tom Sawyer", 3 );
    songList[0][3] = new Song( "Purple Rain", 2 );
    songList[1][0] = new Song( "Sing a Song", 1 );
    songList[1][1] = new Song( "Baba O'Riley", 5 );
    songList[1][2] = new Song( "Jumper", 4 );
    songList[1][3] = new Song( "Car Wash", 3 );
    songList[2][0] = new Song( "Kung Fu Fighting", 2 );
    songList[2][1] = new Song( "Right as Rain", 4 );
    songList[2][2] = new Song( "Beat It", 5 );
    songList[2][3] = new Song( "Bust a Move", 4 );

    public  String toString()
    {
        String output = " ";
        for (int row = 0; row < songList.length; row++)
        {
            for (int col = 0; col < songList[row].length; col++)
            {
                output+=(songList[row][col]);
            }
            output += "\n";
        }
        return output;
    }

}

Answer 1

您需要在方法中执行以下所有操作:

songList[0][0] = new Song("Jet Airliner", 5 );

songList[0][1] = new Song( "Slide", 4 );

songList[0][2] = new Song( "Tom Sawyer", 3 );
songList[0][3] = new Song( "Purple Rain", 2 );
songList[1][0] = new Song( "Sing a Song", 1 );
songList[1][1] = new Song( "Baba O'Riley", 5 );
songList[1][2] = new Song( "Jumper", 4 );
songList[1][3] = new Song( "Car Wash", 3 );
songList[2][0] = new Song( "Kung Fu Fighting", 2 );
songList[2][1] = new Song( "Right as Rain", 4 );
songList[2][2] = new Song( "Beat It", 5 );
songList[2][3] = new Song( "Bust a Move", 4 );

因此，您可以创建一个init()方法，或者根据需要创建一个构造函数。

public void init(){
    songList = new String[3][4];
    songList[0][0] = new Song("Jet Airliner", 5 );

    songList[0][1] = new Song( "Slide", 4 );

    songList[0][2] = new Song( "Tom Sawyer", 3 );
    songList[0][3] = new Song( "Purple Rain", 2 );
    songList[1][0] = new Song( "Sing a Song", 1 );
    songList[1][1] = new Song( "Baba O'Riley", 5 );
    songList[1][2] = new Song( "Jumper", 4 );
    songList[1][3] = new Song( "Car Wash", 3 );
    songList[2][0] = new Song( "Kung Fu Fighting", 2 );
    songList[2][1] = new Song( "Right as Rain", 4 );
    songList[2][2] = new Song( "Beat It", 5 );
    songList[2][3] = new Song( "Bust a Move", 4 );
}

现在，在调用toString()的JukeBox方法之前，您需要先调用init()方法。