使用bzero或者memset对每维清零后赋不起值

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

int main()
{
        char buf[3][3];
        int i;
        int j;

        for (i = 0; i < 3; i++) {
            for (j = 0; j < 3; j++) {
                bzero(buf[i], 3);
                buf[i][j] = '1';
                printf("buf[%d][%d]:%c\n", i, j, buf[i][j]);                                
            }
        }
        for (i = 0; i < 3; i++) {                                                                    
            for (j = 0; j < 3; j++) {                                                                    
                printf("%p,%p\n", buf[i], &buf[i][j]);                                             
                printf("buf[%d][%d]:%c\n", i, j, buf[i][j]);
            }                                                                           
        }

        return 0;
}
// buf[]每个维度（指针）地址我也打印出来没问题的，但是bzero后就是赋不起值，请问各位大佬是怎么回事呢