How to create head node - c

Question

I think I got it wrong in newList. Typedef struct implementations must not be change. This is a lab assignment in my school.. Thanks in advance :)
#include<stdio.h>
typedef struct node *nodeptr;
struct node {
int item;
nodeptr next;
};
typedef nodeptr List;
List newList();
newList creates a header and returns a pointer to the header node
void display(List list);
void addFront(List list, int item);
List newList(){
List list;
list=(nodeptr)malloc(sizeof(List));
list->next=NULL;
return list;
} //I think my new list is incorrect..
void display(List list){
nodeptr ptr=list;
while(ptr!=NULL){
printf("%d",ptr->item);
ptr=ptr->next;
}
printf("\n");
}
void addEnd(List list, int item){
nodeptr temp, ptr;
temp=(List)malloc(sizeof(nodeptr));
temp->item=item;
temp->next=NULL;
if(list->next==NULL)
list=temp;
else{
ptr=list;
while(ptr->next!=NULL)
ptr=ptr->next;
ptr->next=temp;
}
}
I can't seem to add 10 from the list..
int main(void){
List list=newList();
addEnd(list,10);
display(list);
}

Answer 1

There are many ways you can go about this depending on what you actually want (because just creating a node doesn't make a lot of sense by itself). But generally you have three common options — create it on the stack, create that node in the global memory, or allocate it dynamically. Below are some examples.
On stack
#include <stdlib.h>
struct node {
int item;
struct node *next;
};
int main()
{
struct node head;
head.item = 0;
head.next = NULL;
/* Do something with the list now. */
return EXIT_SUCCESS;
}
In Global Memory
#include <stdlib.h>
struct node {
int item;
struct node *next;
};
static struct node head;
int main()
{
/* Do something with the list now. */
return EXIT_SUCCESS;
}
Dynamic Allocation
#include <stdlib.h>
#include <stdio.h>
struct node {
int item;
struct node *next;
};
int main()
{
struct node *head;
head = calloc(1, sizeof(struct node));
if (head == NULL) {
perror("calloc");
return EXIT_FAILURE;
}
/* Do something with the list now. */
return EXIT_SUCCESS;
}
You can read up on any of the above example in any introductory C book.
Hope it helps. Good Luck!