Can anyone explain this code

Question

#include <stdio.h>
extern int x;

int main() {
do{
do{
printf("%o", x);
}
while(!-2);
}
while(0);
return 0;
}
int x =8;

Answer 1

%o is for octal number.
1000 -> this is 8 in binary
For octal you group three elements from LSB but 1 will be left out alone. So to get 3 bit combination you add two 0's before 1.
001000 -> now if you group 3 bits from right you get 0 and three bits on left will give you 1.
So your output is 10.

Also if you did not understand the while loop then both are false since -2 will give true but the ! operator results in false.

Answer 2

AnonymousGuy yeah for confusing people thanks for help 👍

Answer 3

External is a storage class like auto ,static I think it is global

Answer 4

Yeah..like Avinesh said the code simply converts an integer in octal value...

But I would like to ask you Preity.. from where you found this code?? Bcoz I don't see any use of two do-while loops in this code..

Answer 5

Thanks @all

Answer 6

AnonymousGuy I'm preparing for Gate and these all questions are in question bank of gate which in referring

Answer 7

Preity Okay..Then I guess these loops are just for confusing people😅