How to declare struct variable with in the main function in c? - c

Question

I am new for c programming, my code is working but my question is, if I declare struct node *a,*b; in main function ,how to passing a and b to void create() .And why it's not working, can someone please help me understand it?
#include<stdio.h>
#include<conio.h>
#include<malloc.h>
struct node
{
int d;
struct node *next;
}*start=NULL;struct node *a,*b; //move this part to main function -> struct node *a,*b; but its not working
void create()
{
a=(struct node *)malloc(sizeof(struct node));
printf("Enter the data : ");
scanf("%d",&a->d);
a->next=NULL;
if(start==NULL)
{
start=a;
b=a;
}
else
{
b->next=a;
b=a;
}
}
void display()
{
struct node *a;
printf("\nThe Linked List : ");
a=start;
while(a!=NULL)
{
printf("%d--->",a->d);
a=a->next;
}
printf("NULL\n");
}
void main()
{
char ch;
do
{
create();
printf("Do you want to create another : ");
ch=getche();
}
while(ch!='n');
display();
}
void freenodes()
{
struct node *a;
a = start;
while(a != NULL)
{
struct node *freenode = a ;
a = a->next;
free(freenode) ;
}
}

Answer 1

void main()
{
struct node name_of_varialbe;//this is struct variable declaration
...
}

Answer 2

Just change the prototype of void create() to void create(struct node *,struct node *) and call this way:
char ch;
do
{
struct node *a_main=(struct node *)malloc(sizeof(struct node));
struct node *b_main=(struct node *)malloc(sizeof(struct node));
create(a_main,b_main);
printf("Do you want to create another : ");
ch=getche();
}while(ch!='n');
void create(struct node *a,struct node *b)
{
//do your stuff
}