Thread: Help With Structures

Hello I wrote this code but it's not working. I would be very greatful if anyone could help me out. It passes the structure as a function parameter into another function and returens it's values for the desired variable. I will be very graet full if anyone could help me and point out the mistakes.

Code:

#include <stdio.h>

float test(information_t in);

typedef struct{
	int number;
	int place;
	int postcode;
} information_t;

int main()
{
	information_t information;
	information *in;
	
printf(" Please enter the number: ");
scanf(" %d",&information.number);

printf(" Please enter the place: ");
scanf(" %d",&information.place);

printf(" please enter the postcode: ");
scanf(" %d",&information.postcode);

test(information_t in);

return 0;
}

float (information_t in)
{
	char position;
	position= scanf(" %d%d%d", in->number, in->place, in->postcode);
	
return(position);
}

Thanks cwr for your advice it really did help clear up a few things.

But I just don'nt know how to pass the parameter to the gunction test. I want to pass the sturcture as a function parameter and uses it's variables in the new function. I was hoping If somebady can show me how to do it.

Code:

#include <stdio.h>

typedef struct{
	int number;
	int place;
	int postcode;
} information_t;

int test(information_t *in);

int main()
{
	information_t information;
	information *in;
	
printf(" Please enter the number: ");
scanf(" %d",&information.number);

printf(" Please enter the place: ");
scanf(" %d",&information.place);

printf(" please enter the postcode: ");
scanf(" %d",&information.postcode);

test(&information_t  *in);

return 0;
}

int test(information_t  *in)
{
	int position;
	position= scanf(" %d%d%d", &in->number, &in->place, &in->postcode);
	
return(position);
}

Originally Posted by HAssan

Code:

	information_t information;
	information *in;

what do you think this section of code is doing? information is a variable of type struct. You cannot create a pointer to a variable in this manner. You could, however do something like this:

Code:

information_t information;
information_t * in = &information;

which will create a pointer to the variable information of type "information_t". I think this is what you are trying to accomplish (just guessing though).

Code:

test(&information_t  *in);

ABSOLUTELY WRONG.
Your function test takes a variable of type pointer-to-information_t. You are passing it the address of a structure (which i'm not sure if this even exists) and then a dereference of a pointer-to-(variable of type information_t), which is of course not valid at all.

You need to have something like this

Code:

some_int_variable = test(in);

or more simply without the pointer declaration earlier

Code:

some_int_variable = test(&information);

which of course assumes that some_int_variable is declared earlier as an int.

Which leads me to my next point: Why does your test function return an int? It serves no purpose. Why not just use void return type?