why o/p like this ?

[Sweety]

void main()
{
int val=2;
val = - --val- val-- - --val;
printf("%d",val);
}
o/p-> -1

 

[Gordon Burditt]

void main()

{
int val=2;
val = - --val- val-- - --val;
printf("%d",val);
}
o/p-> -1

This program ought to invoke the death penalty, and that's just
for the void main() part.

There is no wrong output from this program. It invokes the wrath
of undefined behavior. Even "supercalifragilisticexpealidocious"
or a live grenade without the pin is valid output..

Gordon L. Burditt

 

[Keith Thompson]

void main()
{
int val=2;
val = - --val- val-- - --val;
printf("%d",val);
}
o/p-> -1

You're invoking undefined behavior; the result could be anything.

See the C FAQ <http://www.eskimo.com/~scs/C-faq/faq.html>, section 3.
You should serioulsy consider reading the entire FAQ while you're at
it. The HTML version hasn't been updated lately; the compressed plain
text version at <ftp://ftp.eskimo.com/u/s/scs/C-faq/faq.gz> is the
most current one available.