#include <stdio.h>
void main()
{
printf("%d", printf("%d",printf("Hello world!\n")));
}
Why this gives output as 132 ? hello world is 13 units long.
2 Answers
You may be able to see what's happening more clearly if you split the statement into several statements:
int temp1 = printf("Hello world!\n");
int temp2 = printf("%d", temp1);
printf("%d", temp2);
The first printf prints Hello world!\n. Since this is 13 characters, it returns 13.
The second printf prints 13. Since this is 2 characters, it returns 2.
The third printf prints 2.
So the full output will be:
Hello world!
132
It would have been more obvious what's going on if you added more newlines:
printf("%d\n", printf("%d\n",printf("Hello world!\n")));
would print:
Hello world!
13
3
5 Comments
Dhruba Goswami
thank you, i got it. I thought it was one hundred and thirty two.
Barmar
It would have been less confusing if you put spaces or newlines after the numbers.
Dhruba Goswami
actually it's returning Hello world! 13 3 is it for the new line ?
Lundin
@DhrubaGoswami Yep, you're getting the hang of it now :) I think that last 2 was just a typo here.
Barmar
@Lundin Not a typo, just forgot that the change would have a secondary effect, I hadn't actually tried it.
open man 3 printf and check what it returns
Upon successful return, these functions return the number of characters printed (excluding the null byte used to end output to strings).
In your case printf("Hello world!\n") 1st it prints Hello world! and then returns no of printable char which is 13 and again it prints 2 as 13 has 2 char.
printf()function.