java - Java 中的多维数组 - 为什么会发生错误？

Question

我编写这个类(class)是为了一些测试目的。

public class Crap {
    public static void main(String[] args) {
        int[][] k = new int[2][];
        k[0] = {1};
        k[1] = {2,3};
        System.out.println(k[0][0]);
        System.out.println(k[0][1]);
        System.out.println(k[1][0]);
        System.out.println(k[1][1]);
    }
}

编译时出现以下错误。

Crap.java:5: error: illegal start of expression
        k[0] = {1};
               ^
Crap.java:5: error: not a statement
        k[0] = {1};
                ^
Crap.java:5: error: ';' expected
        k[0] = {1};
                 ^
Crap.java:6: error: ']' expected
        k[1] = {2,3};
          ^
Crap.java:6: error: ';' expected
        k[1] = {2,3};
           ^
Crap.java:6: error: illegal start of type
        k[1] = {2,3};
             ^
Crap.java:6: error: <identifier> expected
        k[1] = {2,3};
              ^
Crap.java:6: error: ';' expected
        k[1] = {2,3};
                ^
Crap.java:6: error: illegal start of type
        k[1] = {2,3};
                 ^
Crap.java:6: error: <identifier> expected
        k[1] = {2,3};
                  ^
Crap.java:6: error: ';' expected
        k[1] = {2,3};
                   ^
Crap.java:7: error: <identifier> expected
        System.out.println(k[0][0]);
                          ^
Crap.java:7: error: ']' expected
        System.out.println(k[0][0]);
                             ^
Crap.java:7: error: ')' expected
        System.out.println(k[0][0]);
                              ^
Crap.java:7: error: ']' expected
        System.out.println(k[0][0]);
                                ^
Crap.java:7: error: illegal start of type
        System.out.println(k[0][0]);
                                 ^
Crap.java:7: error: <identifier> expected
        System.out.println(k[0][0]);
                                  ^
Crap.java:8: error: <identifier> expected
        System.out.println(k[0][1]);
                          ^
Crap.java:8: error: ']' expected
        System.out.println(k[0][1]);
                             ^
Crap.java:8: error: ')' expected
        System.out.println(k[0][1]);
                              ^
Crap.java:8: error: ']' expected
        System.out.println(k[0][1]);
                                ^
Crap.java:8: error: illegal start of type
        System.out.println(k[0][1]);
                                 ^
Crap.java:8: error: <identifier> expected
        System.out.println(k[0][1]);
                                  ^
Crap.java:9: error: <identifier> expected
        System.out.println(k[1][0]);
                          ^
Crap.java:9: error: ']' expected
        System.out.println(k[1][0]);
                             ^
Crap.java:9: error: ')' expected
        System.out.println(k[1][0]);
                              ^
Crap.java:9: error: ']' expected
        System.out.println(k[1][0]);
                                ^
Crap.java:9: error: illegal start of type
        System.out.println(k[1][0]);
                                 ^
Crap.java:9: error: <identifier> expected
        System.out.println(k[1][0]);
                                  ^
Crap.java:10: error: <identifier> expected
        System.out.println(k[1][1]);
                          ^
Crap.java:10: error: ']' expected
        System.out.println(k[1][1]);
                             ^
Crap.java:10: error: ')' expected
        System.out.println(k[1][1]);
                              ^
Crap.java:10: error: ']' expected
        System.out.println(k[1][1]);
                                ^
Crap.java:10: error: illegal start of type
        System.out.println(k[1][1]);
                                 ^
Crap.java:10: error: <identifier> expected
        System.out.println(k[1][1]);
                                  ^
Crap.java:12: error: class, interface, or enum expected
}
^

Answer 1

需要初始化第二维数组..语法如下:

k[0] = new int[]{1};
k[1] = new int[]{2,3};