sizeof() returning different values even when the two variables contain the same string

Question

I am getting different values on sizeof for the same string value.

when I run the below code in C:

char str[] = "November";
char *s = "November";
printf(" str[] = %ld\n",sizeof(str));
printf(" *s = %ld\n",sizeof(s));

expected output:

str[] = 9
*s = 9

Actual output:

str[] = 9
*s = 8

What is going on actually?

Read about the [sizeof operator](https://en.cppreference.com/w/cpp/language/sizeof) — Mike Kinghan, Dec 20 '18 at 08:40

score 4 · Answer 1 · answered Dec 20 '18 at 08:39

4

sizeof(str) is the size of char array str which contains 9 elements (including the null terminator) and therefore 9 bytes.
sizeof(s) is the size of pointer to char which is 8 bytes on your system

answered Dec 20 '18 at 08:39

P.W

is there any way to get the size of the string from *s? – Sijo John Dec 20 '18 at 10:26
No. `*s` is now the first character of the string, so `sizeof(*s)` will be 1. – P.W Dec 20 '18 at 10:33

score 3 · Answer 2 · answered Dec 20 '18 at 08:37

3

sizeof() is not strlen()

the size of a pointer is not the size of the pointed element

answered Dec 20 '18 at 08:37

bruno

2 Answers2