Expected expression before 'Node' - c

Question

I've been messing aroung with the linked list implementation in C and got stuck at this problem: why is it giving me expected expression before 'Node' in the following lines?:
Node *newNode1= malloc(sizeOf(Node));
Node *newNode2= malloc(sizeOf(Node));
Node *newNode3= malloc(sizeOf(Node));
Node *newNode4= malloc(sizeOf(Node));
I've never seen such problems in C before. What went wrong ?
Code:
#include <stdio.h>
#include <stdlib.h>
typedef struct Node_{
int data;
struct Node_ *next;
}Node;
void insertNodeBegin(Node **head, Node *newNode){
if((*head)==NULL){
(*head)->next = NULL;
*head = newNode;
}
else{
newNode->next = (*head)->next;
(*head)->next = newNode;
}
}
void printList(Node *head){
Node *current = head;
while(current != NULL){
printf("%d ", current->data);
current = current->next;
}
}
int main()
{
Node *head = NULL;
Node *newNode1= malloc(sizeOf(Node));
newNode1->data = 12;
Node *newNode2 = malloc(sizeOf(Node));
newNode2->data = 16;
Node *newNode3 = malloc(sizeOf(Node));
newNode3->data = 55;
Node *newNode4 = malloc(sizeOf(Node));
newNode4->data = 8;
insertNodeBegin(&head, newNode1);
insertNodeBegin(&head, newNode2);
insertNodeBegin(&head, newNode3);
insertNodeBegin(&head, newNode4);
printList(head);
return 0;
}

Answer 1

sizeOf(Node) should be sizeof(Node), note the small o. After all this is C, not Java. :)

Answer 2

In short reorder if commands inside insertNodeBegin()
if(*head == NULL){
*head = newNode;
(*head)->next = NULL;
}
Because in first execution of program head points to NULL and for it we haven't any allocated memory. As head in first execution not points to a Node location using head -> next not valid and cause segmentation fault in run time.
In node creation with malloc() we must check is memory allocation successful or not. for that i use createNode() function.
We check if memory allocation for Node is OK then add that Node to list. And finally Use void as main(void) argument.
After these change your code becomes
Code
#include <stdio.h>
#include <stdlib.h>
typedef struct Node_{
int data;
struct Node_ *next;
}Node;
void insertNodeBegin(Node **head, Node *newNode){
if(*head == NULL){
*head = newNode;
(*head)->next = NULL;
}
else{
newNode->next = (*head)->next;
(*head)->next = newNode;
}
}
void printList(Node *head){
Node *current = head;
while(current != NULL){
printf("%d ", current->data);
current = current->next;
}
}
int createNode(Node **node, int value){
*node = malloc(sizeof(Node));
if(*node){
(*node)->data = value;
return 1;
}else{
fprintf(stdout, "%s", "can't allocate ...\n");
return 0;
}
}
int main(void)
{
Node *head = NULL;
Node *newNode1;
Node *newNode2;
Node *newNode3;
Node *newNode4;
if(createNode(&newNode1, 12)) {
insertNodeBegin(&head, newNode1);
}
if(createNode(&newNode2, 16)) {
insertNodeBegin(&head, newNode2);
}
if(createNode(&newNode3, 55)) {
insertNodeBegin(&head, newNode3);
}
if(createNode(&newNode4, 8)) {
insertNodeBegin(&head, newNode4);
}
printList(head);
return 0;
}