what is the output

[singer_shant]

what is the output and how is it?

[SMurf]

You're the "programmer", you tell me.

[singer_shant]

For the file "output" which I've sent the o/p is 4.
but how is it 4 I dont know.

[Quantum1024]

#include<stdio.h>
#include<conio.h>
void main()
{
clrscr();
for(int i=0;i<=3;i++);
printf("%d",i);
getch();
}

This would output the numbers 0 to 3.

You have some problems

• use of non-standard header, conio.h
• Use of void main
• Use of non-standard function, clrscr()

[singer_shant]

can u plz explain me what do u mean by non-standard header, conio.h?

[singer_shant]

if we put a semi colon ( at the end of any loop it would go into infinite loop but y it is giving the o/p as the values from 0 to3?

[Quantum1024]

conio is not part of the c standard and isn't included in many compilers. So your code won't compile on many compilers. This is only a problem if you want to make your code portable or make it available to others or are trying to learn standard, portable c.

[fgw_three]

if we put a semi colon ( at the end of any loop it would go into infinite loop but y it is giving the o/p as the values from 0 to3?

Not with a for loop. The for loop will run to its conclusion because it contains the condition which will cause it to cease looping.

Your statement:

for(int i=0;i<=3;i++);

is really:

for (int i = 0; i <= 3; i++)
   ;

which means loop as long as i is less than 3, doing nothing in the loop.

At the end of the loop, i has already been set to 4, it falls out of the loop because the condition is no longer true, and 4 is output to stdout.

hope this helps.....

[singer_shant]

thank you fgw_three. I did get u.

[singer_shant]

but if the question is like this :


for(;;


then what is the output

[cwr]

but if the question is like this :

                for(;;);

then what is the output

That is an infinite loop, it won't exit.

If you need to do something with ";)" in a post, be sure to check "Disable smilies in text" before you post.

[fgw_three]

That is an infinite loop, it won't exit.

If you need to do something with "" in a post, be sure to check "Disable smilies in text" before you post.

Yep -- that's one way that you can infinite loop with a for.

I tend to avoid that one, though. While there ARE times that you want to loop infinitely and exit the program from within the loop, I usually use something along the lines of

while (1) {
  /*do something, exit from within here */
}

instead of

for (;;) {
  /* do something, exit from wthin here */
}

Just habit I guess....