Whats wrong with this c code(linked list implementation)?

Question

 //linked list implementation 
 #include<stdio.h>
 #include<stdlib.h>
 struct node
 {
   int data;
   struct node* link;
  };
 struct node* head;
 void insert(int);
 void print();
 int main()
 {
   head=NULL;
   int n,i,x;
   printf("\nEnter the number of elements :");
   scanf("%d",&n);
   for(i=0;i<n;i++)
   {
     printf("\nEnter the element :");
     scanf("%d",&x);
     insert(x);
     print();
   }
   }

   void insert(int x)
   {
     struct node* temp=(node*)malloc(sizeof(struct node));
     temp->data=x;
     temp->link=head;
     head=temp;
   }
   void print()
   {
     struct node* temp=head;
     int i=0;
     printf("\nThe list is ");
     while(temp!=NULL)
     {
       printf("%d ",temp->data);
       temp=temp->link;
     }
     printf("\n");
     }

While compiling the code:

In function 'insert':
28:24: error: 'node' undeclared (first use in this function)
     struct node* temp=(node*)malloc(sizeof(struct node));
                        ^
28:24: note: each undeclared identifier is reported only once for each function it appears in
28:29: error: expected expression before ')' token
     struct node* temp=(node*)malloc(sizeof(struct node));
                             ^

`(node*)` should be `(struct node*)` Voting to close as a typo. — Sergey Kalinichenko, Nov 13 '15 at 15:18
Use `typedef struct node {/*ToDo - add members here*/} node` for less typing. — Bathsheba, Nov 13 '15 at 15:20
This: `struct node* temp=(node*)malloc(sizeof(struct node));` should be written as `struct node *temp = malloc(sizeof *temp);`. — unwind, Nov 13 '15 at 15:25

score 7 · Accepted Answer · edited May 23 '17 at 12:15

7

node* is not the same as struct node* in this context in C as it is for C++.
Try to avoid superfluous casts in C. Actually, try to avoid superfluous casts in any language where it is not required. Do I cast the result of malloc?

edited May 23 '17 at 12:15

Community

1
1

answered Nov 13 '15 at 15:22

John Park · Answer 2 · 2015-11-13T15:22:28.163

1

Change the following statement

struct node* temp=(node*)malloc(sizeof(struct node));

into,

struct node* temp=(struct node*)malloc(sizeof(struct node));

Sometimes I do make similar mistakes.

edited Nov 13 '15 at 15:22

answered Nov 13 '15 at 15:21

John Park

1,644
1
12
17

3

A cast of `malloc`? You bad man. – Bathsheba Nov 13 '15 at 15:21
There is no need to cast malloc in C. My point is, if we give such a short answer you could avoid casting malloc with an Explanation. – Michi Nov 13 '15 at 15:24

Whats wrong with this c code(linked list implementation)?

2 Answers2