description about error in following prog

[vivek verma]

[code]
main()
{
extern int i;
i=20;
print("%d",sizeof(i));
}
[\code]

[donbock]

Please tell us why you think there is an error in this program. Did you get a build error? Was there something wrong with the output?

[vivek verma]

error at compile time and error is
LINKER ERROR :undefined symbol i

[Joseph Martell]

You declared i as

extern int i;

Notice that this is a declaration, not a definition. You basically told the linker that you are relying on i being defined in another place, but the linker couldn't find any definition for i.

Is there a reason that you need the extern keyword? Dropping it should allow this to compile just fine.

Oh, and a technical point: this is actually a link error, not a compilation error. Its worth reading a little bit about the differences. It can help with your troubleshooting.

[vivek verma]

thanks
I got my ans