What's wrong of the the code for making a list??

[Mars]

I followed the reference about ADT,
and wrote something like below....


#include <stdio.h>

/* I intend to make this a list */
struct node_s
{
int x;
struct node_s * next;
};

typedef struct node_s node;

int main(void)
{
node anode;

/* is this corrent? */
anode.next=(node *)malloc(sizeof(node));

anode.next.x=1;

return 1;
}


The code gives

"error: request for member 'x' in something not a structure or union"

 

[pete]

I followed the reference about ADT,
and wrote something like below....

#include <stdio.h>

/* I intend to make this a list */
struct node_s
{
int x;
struct node_s * next;
};

typedef struct node_s node;

int main(void)
{
node anode;

/* is this corrent? */
anode.next=(node *)malloc(sizeof(node));

anode.next.x=1;

return 1;
}

The code gives

"error: request for member 'x' in something not a structure or union"

#include <stdio.h>
#include <stdlib.h>

struct node_s
{
int x;
struct node_s *next;
};

typedef struct node_s node;

int main(void)
{
node anode;

anode.next = malloc(sizeof *anode.next);
anode.next -> x = 1;
printf("%d\n", anode.next -> x);
free(anode.next);
return 0;
}

 

[Al Bowers]

I followed the reference about ADT,
and wrote something like below....


#include <stdio.h>

You need the header for function malloc.

/* I intend to make this a list */
struct node_s
{
int x;
struct node_s * next;
};

typedef struct node_s node;

int main(void)
{
node anode;

/* is this corrent? */
anode.next=(node *)malloc(sizeof(node));

You do not need the cast. Also, check the return value
of function malloc to make sure the allocated occurred.

anode.next.x=1;

anode.next is a pointer. You either need to use the *
operator or the -> operator.
(*anode.next).x = 1;
or
anode.next->x = 1;

 

[Mars]

Thx~~~~~~~~~~~~~~~~!!!!