what is the difference between one length of char*/char[] and char in C?

Question

char str[] = "a";
char ch = 'a';

speaking of the difference between the two, we all know str point to a memory space which stored [a, \0], but I want to ask whether there is a difference between str[0] and ch ?

Answer 1

but I want to ask whether there is a difference between str[0] and ch ?

No.

str[0] and ch , both are of type char , and hold the value 'a' . From this aspect (type and value), there is no difference.