打印时获取类似于数组值的内存地址(C编程)

Question

我正在尝试创建8x8数组，但是当我打印该数组时，在7个元素之后，我没有得到在创建数组时分配的确切值。我的数组如下

#include <stdio.h>
int main() {
    int puzzle[8][8] = {
    //   0 1 2 3 4 5 6 7 8 
        {0,0,2,0,4,0,5,9,3},//0
        {7,0,0,3,1,0,4,0,8},//1
        {4,0,0,8,0,5,1,0,2},//2
        {8,3,0,2,0,0,0,0,0},//3
        {0,9,6,0,0,0,3,5,0},//4
        {0,0,0,0,0,4,0,8,6},//5
        {3,0,1,5,0,9,0,0,7},//6
        {6,0,5,0,2,8,0,0,1},//7
        {0,4,0,0,7,0,6,0,0} //8
    }; 
for (int i = 0; i < 9; ++i)
  {
    for (int j = 0; j < 9; ++j)
    {
      printf("\n puzzle[%d][%d] = %d",i,j,puzzle[i][j]);
    }
  }


    return 0;
}

我得到的输出是

 puzzle[0][0] = 0
     puzzle[0][1] = 0
     puzzle[0][2] = 2
     puzzle[0][3] = 0
     puzzle[0][4] = 4
     puzzle[0][5] = 0
     puzzle[0][6] = 5
     puzzle[0][7] = 9
     puzzle[0][8] = 7
     puzzle[1][0] = 7
     puzzle[1][1] = 0
     puzzle[1][2] = 0
     puzzle[1][3] = 3
     puzzle[1][4] = 1
     puzzle[1][5] = 0
     puzzle[1][6] = 4
     puzzle[1][7] = 0
     puzzle[1][8] = 4
     puzzle[2][0] = 4
    puzzle[2][1] = 0
     puzzle[2][2] = 0
     puzzle[2][3] = 8
     puzzle[2][4] = 0
     puzzle[2][5] = 5
     puzzle[2][6] = 1
     puzzle[2][7] = 0
     puzzle[2][8] = 8
     puzzle[3][0] = 8
     puzzle[3][1] = 3
     puzzle[3][2] = 0
     puzzle[3][3] = 2
     puzzle[3][4] = 0
     puzzle[3][5] = 0
     puzzle[3][6] = 0
     puzzle[3][7] = 0
     puzzle[3][8] = 0
     puzzle[4][0] = 0
     puzzle[4][1] = 9
     puzzle[4][2] = 6
     puzzle[4][3] = 0
     puzzle[4][4] = 0
     puzzle[4][5] = 0
     puzzle[4][6] = 3
     puzzle[4][7] = 5
     puzzle[4][8] = 0
     puzzle[5][0] = 0
     puzzle[5][1] = 0
     puzzle[5][2] = 0
     puzzle[5][3] = 0
     puzzle[5][4] = 0
     puzzle[5][5] = 4
     puzzle[5][6] = 0
     puzzle[5][7] = 8
     puzzle[5][8] = 3
     puzzle[6][0] = 3
     puzzle[6][1] = 0
     puzzle[6][2] = 1
     puzzle[6][3] = 5
     puzzle[6][4] = 0
     puzzle[6][5] = 9
     puzzle[6][6] = 0
     puzzle[6][7] = 0
     puzzle[6][8] = 6
     puzzle[7][0] = 6
     puzzle[7][1] = 0
     puzzle[7][2] = 5
     puzzle[7][3] = 0
     puzzle[7][4] = 2
     puzzle[7][5] = 8
     puzzle[7][6] = 0
     puzzle[7][7] = 0
     puzzle[7][8] = -445142480
     puzzle[8][0] = -445142480
     puzzle[8][1] = 32765
     puzzle[8][2] = 480800256
     puzzle[8][3] = -129200335
     puzzle[8][4] = 0
     puzzle[8][5] = 0
     puzzle[8][6] = -2108403533
     puzzle[8][7] = 32522
     puzzle[8][8] = -2106304992

正如你所看到的，我并没有得到我分配给第七位的确切值。我得到的输出看起来像地址或ids。我不明白为什么会发生这种情况，这是一个问题，还是我的代码中有任何错误？

Answer 1

正如您已经了解到的，数组元素从零开始被索引。因此，当定义大小为n arr[n]的数组时，只能在这个数组中保存n元素(0到n-1)。多维数组也是如此。

在您的示例中，您只定义了一个大小为8x8的数组，该数组只能容纳64个元素。但是您正在尝试将9x9 81元素分配给您的数组。因此，只有索引puzzle[0][0]到puzzle[7][7]是可访问的。

Answer 2

编译器将发出用于此初始化的消息。

int puzzle[8][8] = {
//   0 1 2 3 4 5 6 7 8 
    {0,0,2,0,4,0,5,9,3},//0
    {7,0,0,3,1,0,4,0,8},//1
    {4,0,0,8,0,5,1,0,2},//2
    {8,3,0,2,0,0,0,0,0},//3
    {0,9,6,0,0,0,3,5,0},//4
    {0,0,0,0,0,4,0,8,6},//5
    {3,0,1,5,0,9,0,0,7},//6
    {6,0,5,0,2,8,0,0,1},//7
    {0,4,0,0,7,0,6,0,0} //8
};

因为数组的元素是带有8元素的数组，但是您为每个元素提供了9初始化程序。

如果数组有N元素，那么有效的索引范围是[0, N)。