C中8x8x2数组中的垃圾输出

Question

我正在尝试表示一个 8x8 笛卡尔平面，其内容将是长度为 2 的字符串。我想尽可能地保持这种方案的类型安全并这样做：

typedef char cartesian[8][8][2];
cartesian xy;

for(int i=0; i<8; i++){
        for(int j=0; j<8; j++){
                xy[i][j][0] = ' '
                xy[i][j][1] = ' '
        }
}

// The first element would represent some kind of information, and the other one 
// would be just elements like '+' or '*'. In other cases, this would be 'EMPTY',
// it means a double space.

xy[2][4][0] = 'B';
xy[2][4][1] = '+';

// The right printing method (cause it doesn't have any trash) would be:

for(int i=0; i<8; i++){
        for(int j=0; j<8; j++){
                printf("| %c%c ", xy[i][j][0], xy[I][j][1] );
        }
        printf("|\n");
}

但问题是：为什么输出垃圾带有 printf("| %s ", xy[i][j][]); ？ 我知道这可能是个愚蠢的问题，但我现在累了。

提前致谢。

顺便说一句，分配不起作用。我的意思是：xy[2][4][] = "B+";。

Answer 1

这是您重写的代码。请注意，cartesian 现在是 [8][8][3] 并且 strcpy 用于填充最后一个数组维度。为了清楚起见，我将 xy 清除为一个单独的函数。

#include <stdio.h>
#include <string.h>

typedef char cartesian[8][8][3];

void clearXY(cartesian *xy)
{
    for (int i = 0; i < 8; i++) {
        for (int j = 0; j < 8; j++) {
            strcpy((*xy)[i][j], "  ");
        }
    }
}

int main(int argc, char *argv[])
{
    cartesian xy;

    // The first element would represent some kind of information, and the other one 
    // would be just elements like '+' or '*'. In other cases, this would be 'EMPTY',
    // it means a double space.
    clearXY(&xy);

    strcpy(xy[2][4], "B+");

    printf("-------- Method 1 --------\n");
    for (int i = 0; i < 8; i++) {
        for (int j = 0; j < 8; j++) {
            printf("| %c%c ", xy[i][j][0], xy[i][j][1]);
        }
        printf("|\n");
    }

    printf("-------- Method 2 --------\n");
    for (int i = 0; i < 8; i++) {
        for (int j = 0; j < 8; j++) {
            printf("| %s ", xy[i][j]);
        }
        printf("|\n");
    }
    printf("-------- Done ------------\n");
}