accessing global variables in c

[manju23reddy]

consider the program
int a = 10;
int main()
{
int a = 20;
}

now i need to acess the global a within main so how to do it.


but i have solution like this
int main()
{
int i = a;
int a = 20;
}

but is there any alternative.

[Billiska]

I think your second example should precisely be:

int a=10;
int main()
{
 int *pa=&a;
 int a=20;
}

Then you can use pa to access the global 'a'

And here a have another way(maybe stupid but it works):

int a=10;
int GetA() {return a;}
int main()
{
 int a=20;
}

With this, you can use GetA() to retrieve 'a'.
I think this one will not work with 'interpreter'. Can anyone make sure of this? Thanks.

[Ganon11]

The best solution is just to not re-use the name 'a'. In larger programs, you will want to give your variables descriptive names, such as 'sum' or 'rateOfInterest ' rather than 1-letter names. In this case, there's not usually a need to have two variables with the same name.

If you are forced into this situation, I believe preceding the variable name with the scope resolution operator "::" will access the global variable.

[gpraghuram]

The best solution is just to not re-use the name 'a'. In larger programs, you will want to give your variables descriptive names, such as 'sum' or 'rateOfInterest ' rather than 1-letter names. In this case, there's not usually a need to have two variables with the same name.

If you are forced into this situation, I believe preceding the variable name with the scope resolution operator "::" will access the global variable.

I believe the :: operator will work only for C++ and not for C

Raghu

[Banfa]

I believe the :: operator will work only for C++ and not for C

I agree, it isn't uncommon in big projects for the coding standard to specify a prefix for global variable names g_ for instance.

[JosAH]

I agree, it isn't uncommon in big projects for the coding standard to specify a prefix for global variable names g_ for instance.

Yep, those are the last hiccups from that preposterous Hungarian whatchamacallit
naming scheme that is heavily used by Microsoft. Ever so handy when the type
or storage rights change for a variable: everything that uses the variable has to
be changed then; hurray!

kind regards,

Jos