Can anyone explain this question?

Question

#include <stdio.h>

int main() {
char str[]="hellow\0rl\0";
printf("%d", sizeof(str));
printf("%s", str);
return 0;
}
After null terminator why the size is counting

Answer 1

sizeof provides the size of the data item, which is the actual size of the space which has been allocated to accommodate the data, not just the length of the string (which ends after being null terminated).

Take for example:

char str[39] = "test";

sizeof(str) returns 39, not 4.

Answer 2

Preity '\0' is only one char (so sum 10) and another '\0' is automatically added at the end, so the sum is 11

Answer 3

++a || b++ is evaluated as such
a is incremented, then tested. It is different from 0 so the or operator evaluate as true and does not evaluate what comes next (b++)
so after that, a == 2, b == 1 and c == 1
Then the && operation
b is evaluated as 1 then decremented and a is decremented then evaluated as 1 so d == 1
So the output should be
1 1 0 1

Answer 4

Baptiste E. Prunier Hatsy Rei thanks
And how this is calculated can you please explain me
#include <stdio.h>

int main() {
int a=1, b=1;
int c= ++a || b++;
int d = b-- && --a;
printf("%d %d %d %d", d, c ,b ,a);
return 0;
}

Answer 5

Preity

you must see why this is calculated like this in C

okay forget about C
think about age old logic gates truth table
for a OR gate i.e. logic OR
1,0 is 1
0,1 is 1
0,0 is 0
1,1 is 1

so u see as its OR it needs only 1 input to be true to get whole output as true..

now when in C you do
z = r && t
if r is true we dont need to see what t is..
t will only be checked if r is false

that is why..
if for 3 variable a,b,c you wish to compute a=b || c and then increment both b and c
its NOT A LEGIT PRACTICE TO DO
a= b++ || c++
cause if b was true i.e 1 c wont get incremented at all..

for and case
think about AND gate
if one input is 0 no requirement to see other...
so if b is false i.e. 0 in a=b++ && c++
c won't get incremented..

Ultimately
ITS NOT AT ALL A GOOD PRACTICE TO DO INCREMENT, DECREMENT AND LOGICAL AND-OR IN ONE STATEMENT JUST TO KEEP IT SHORT.

Answer 6

So in my code 11 is returning so does it remove the last null character as total Is 12