Accessing a global variable when there is a local variable in the same name

[Mohanasundaram]

int i = 10;
int main()
{
int i = 20;
return 0;
}

Hi All,

I want to access the global variable i inside the main. Is there
a way to do this in C?

Regards,
Mohan.

[Martin Ambuhl]

Mohanasundaram wrote:

int i = 10;
int main()
{
int i = 20;
return 0;
}

Hi All,

I want to access the global variable i inside the main. Is there
a way to do this in C?

By not masking it with a redeclaration inside main.

[James Hu]

On 2004-06-25, Mohanasundaram <mo************ @msn.com> wrote:

int i = 10;
int main()
{
int i = 20;
return 0;
}

I want to access the global variable i inside the main. Is there
a way to do this in C?

int i = 10;
int main(void)
{
int *global_i_point er = &i;
int i = 20;

/* ... use global_i_pointe r to access the global variable i
from inside main ... */

return 0;
}

-- James

[Chris Dollin]

Mohanasundaram wrote:

int i = 10;
int main()
{
int i = 20;
return 0;
}

Hi All,

I want to access the global variable i inside the main. Is there
a way to do this in C?

There's the easy way and the smartarse way.

The easy way is to rename the local i to something else, or to rename
the global i to something more sensible (a global variable called "i"
is probably a very bad idea).

The smararse way involves using pointers or nested extern declarations.
I'm not going to tell you the details. Just rename one or both i's.

--
Chris "electric hedgehog" Dollin
C FAQs at: http://www.faqs.org/faqs/by-newsgrou...mp.lang.c.html
C welcome: http://www.angelfire.com/ms3/bchambl...me_to_clc.html

[Vijay Kumar R Zanvar]

"Mohanasundaram " <mo************ @msn.com> wrote in message news:9b******** *************** **@posting.goog le.com...

int i = 10;
int main()
{
int i = 20;
return 0;
}

Hi All,

I want to access the global variable i inside the main. Is there
a way to do this in C?

Regards,
Mohan.

int i = 10;
int main(void)
{
int i = 5;
{
extern int i;
i; /* the expression i will evaluate to 10 */
}
return 0;
}

--
Vijay Kumar R Zanvar
My Home Page - http://www.geocities.com/vijoeyz/

[CBFalconer]

Chris Dollin wrote:

Mohanasundaram wrote:

int i = 10;
int main()
{
int i = 20;
return 0;
}

I want to access the global variable i inside the main. Is there
a way to do this in C?

There's the easy way and the smartarse way.

.... snip ...

Around here, for a question like this, only the smartarse way is
acceptable.

--
Chuck F (cb********@yah oo.com) (cb********@wor ldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home .att.net> USE worldnet address!

[Dan Pop]

In <9b************ *************@p osting.google.c om> mo************@ msn.com (Mohanasundaram ) writes:

int i = 10;
int main()
{
int i = 20;
return 0;
}

Hi All,

I want to access the global variable i inside the main. Is there
a way to do this in C?

Explain why you can't rename one of the two variables.

If this is a homework question, try finding a better instructor. This
issue should NEVER arise in real C programs.

#include <stdio.h>

int i = 10;

int main()
{
int j = i;
int i = 20;
printf("%d\n", j);
return 0;
}

If the value of the global i might change during the execution of main(),
replace the definition of j by

int *p = &i;

but keep it still *before* the definition of the local i, and use *p any
time you need to access the global i.

Dan
--
Dan Pop
DESY Zeuthen, RZ group
Email: Da*****@ifh.de

[Keith Thompson]

CBFalconer <cb********@yah oo.com> writes:

Chris Dollin wrote:

Mohanasundaram wrote:

int i = 10;
int main()
{
int i = 20;
return 0;
}

I want to access the global variable i inside the main. Is there
a way to do this in C?

There's the easy way and the smartarse way.

... snip ...

Around here, for a question like this, only the smartarse way is
acceptable.

The obvious way, as others have mentioned, is to change the name of
the local variable. (Some languages have ways to refer directly to
variables in outer scopes using expanded names; C doesn't. I suspect
that's what the OP was really asking about.)

But the smartarse way, using a pointer, does illustrate what might
sometimes be a relevant point: just because a function doesn't have
direct visibility to a variable (either because it's hidden by a
declaration in an inner scope, or because it's a static variable
declared in another file or function), you can't necessarily assume
that the function can't read or modify the variable.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[Emmanuel Delahaye]

In 'comp.lang.c', James Hu <jx*@despammed. com> wrote:

int i = 10;
int main()
{
int i = 20;
return 0;
}

I want to access the global variable i inside the main. Is there
a way to do this in C?

int i = 10;
int main(void)
{
int *global_i_point er = &i;
int i = 20;

/* ... use global_i_pointe r to access the global variable i
from inside main ... */

return 0;
}

Clever. I'll try to keep it in mind.

--
-ed- get my email here: http://marreduspam.com/ad672570
The C-language FAQ: http://www.eskimo.com/~scs/C-faq/top.html
C-reference: http://www.dinkumware.com/manuals/reader.aspx?lib=c99
FAQ de f.c.l.c : http://www.isty-info.uvsq.fr/~rumeau/fclc/

[Keith Thompson]

Da*****@cern.ch (Dan Pop) writes:

In <9b************ *************@p osting.google.c om>
mo************@ msn.com (Mohanasundaram ) writes:

int i = 10;
int main()
{
int i = 20;
return 0;
}

Hi All,

I want to access the global variable i inside the main. Is there
a way to do this in C?

Explain why you can't rename one of the two variables.

If this is a homework question, try finding a better instructor. This
issue should NEVER arise in real C programs.

#include <stdio.h>

int i = 10;

int main()
{
int j = i;
int i = 20;
printf("%d\n", j);
return 0;
}

If the value of the global i might change during the execution of main(),
replace the definition of j by

int *p = &i;

but keep it still *before* the definition of the local i, and use *p any
time you need to access the global i.

Yes, that will work. It will also create a potential headache for
future maintainers. Code that silently changes behavior when the
order of declarations is changed is not generally a good idea.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.