java如何打印2d数组时间表？

Question

package javaapplication18;

public class JavaApplication18 {


   public static void main(String[] args) {
       String weekdays[][] = new String[7][0];
       weekdays[1][0] = "mon";
       weekdays[2][0] = "tue";
       weekdays[3][0] = "wed";
       weekdays[4][0] = "thur";
       weekdays[5][0] = "fri";
       weekdays[6][0] = "sat";
       String hours[][] = new String[0][5];
       hours[0][1] = "9:30";
       hours[0][2] = "10:30";
       hours[0][3] = "11:30";
       hours[0][4] = "12:30";
       System.out.println(weekdays[7][0]);
   }

}

当我编译它时，它在线程“main”java中给出了异常的错误提示。lang.ArrayIndexOutOfBoundsException:0 在javaapplication18。JavaApplication18。main（JavaApplication18.java:8） 我如何纠正这一点

Answer 1

试试这个

public static void main(String[] args) {
    //way 1
    String weekdays[][] = new String[7][];
    weekdays[0] = new String[] { "sun" };
    weekdays[1] = new String[] { "mon" };
    weekdays[2] = new String[] { "tue" };
    weekdays[3] = new String[] { "wed" };
    weekdays[4] = new String[] { "thur" };
    weekdays[5] = new String[] { "fri" };
    weekdays[6] = new String[] { "sat" };

    //way 2
    String hours[][] = new String[1][5];
    hours[0][0] = "8:30";
    hours[0][1] = "9:30";
    hours[0][2] = "10:30";
    hours[0][3] = "11:30";
    hours[0][4] = "12:30";
    System.out.println(weekdays[1][0]);
}

Answer 2

尝试更改数组大小，并将工作日数组中的7改为6

public static void main(String[] args) {

        String weekdays[][] = new String[7][1];
        weekdays[0][0] = "sun";
        weekdays[1][0] = "mon";
        weekdays[2][0] = "tue";
        weekdays[3][0] = "wed";
        weekdays[4][0] = "thur";
        weekdays[5][0] = "fri";
        weekdays[6][0] = "sat";

        String hours[][] = new String[1][5];
        hours[0][1] = "9:30";
        hours[0][2] = "10:30";
        hours[0][3] = "11:30";
        hours[0][4] = "12:30";
        System.out.println(weekdays[6][0]);
    }

//在评论后回答

public static void main(String[] args) {

        String weekdays[][] = new String[7][7];
        weekdays[0][0] = "sun";

        weekdays[0][1] = "9:30";
        weekdays[0][2] = "10:30";
        weekdays[0][3] = "11:30";

        weekdays[1][0] = "mon";

        weekdays[1][1] = "9:30";
        weekdays[1][2] = "10:30";
        weekdays[1][3] = "11:30";

        weekdays[2][0] = "tue";

        weekdays[2][1] = "9:30";
        weekdays[2][2] = "10:30";
        weekdays[2][3] = "11:30";

        weekdays[3][0] = "wed";

        weekdays[3][1] = "9:30";
        weekdays[3][2] = "10:30";
        weekdays[3][3] = "11:30";

        weekdays[4][0] = "thur";

        weekdays[4][1] = "9:30";
        weekdays[4][2] = "10:30";
        weekdays[4][3] = "11:30";

        weekdays[5][0] = "fri";

        weekdays[5][1] = "9:30";
        weekdays[5][2] = "10:30";
        weekdays[5][3] = "11:30";

        weekdays[6][0] = "sat";

        weekdays[6][1] = "9:30";
        weekdays[6][2] = "10:30";
        weekdays[6][3] = "11:30";

        String hours[][] = new String[1][5];
        hours[0][1] = "9:30";
        hours[0][2] = "10:30";
        hours[0][3] = "11:30";
        hours[0][4] = "12:30";

        int j = 0;
        int i = 0;
        while (i < 7) {
            System.out.print("\t" + weekdays[i][j]);
            j++;
            if (j > 3) {
                j = 0;
                i++;
                System.out.println();
            }
        }
    }

Answer 3

更改数组声明中的数组大小。大小0应为1

声明数组时，索引应至少为一个。因为它告诉我们应该在内存中分配多少空间。但是，如果使用数组后者，则索引是基于0的。如果声明a[7][1]，最后一个数组元素将是a[6][0]

   public static void main(String[] args) {

       String weekdays[][] = new String[7][1];
       weekdays[0][0] = "sun";
       weekdays[1][0] = "mon";
       weekdays[2][0] = "tue";
       weekdays[3][0] = "wed";
       weekdays[4][0] = "thur";
       weekdays[5][0] = "fri";
       weekdays[6][0] = "sat";

       String hours[][] = new String[1][5];
       hours[0][1] = "9:30";
       hours[0][2] = "10:30";
       hours[0][3] = "11:30";
       hours[0][4] = "12:30";
       System.out.println(weekdays[6][0]); // sat
   }

Answer 4

首先，您得到的错误是运行时错误，不应该在编译期间发生。 其次，为了打印一个数组，您需要对其进行迭代，2d数组也是如此

您的代码应该如下所示：

for ( int i = 0; i < weekdays.length ; i++ ){
        for ( int j = 0;  j < weekdays[j].length ; j++ ){
            System.out.println(weekdays[i][j]);
        }
    }