Why can I loop through a char array until NULL terminator when I didn't end the string with one?

Question

Why is it possible to loop through this string until a NULL terminator if I did not end the string with one or give it an extra element to be automatically terminated with one?

char buf[5];
buf[0] = 'H';
buf[1] = 'e';
buf[2] = 'l';
buf[3] = 'l';
buf[4] = 'o';

char *p = buf;

for (p = buf; *p != '\0'; p++)
   ch_printf(ch, "%c\n", *p);

I am a newbie to C, attempting to teach myself, so please forgive my stupidity :)

Thank you for your help.

Answer 1

这是因为您尝试访问未分配的内存，因此buf [5]的结果为null