Thread: Hase Table - compiling error

Hi ,
Could you please help me whith this error?

:86:16: error:
invalid operands to binary == (have ‘IP_addres’ and ‘IP_addres’)

Code:

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


typedef struct
{
  long l;
  union
  {
      unsigned int lo:16;
      unsigned int hi:16;

  }s;

}IP_addres;

typedef struct Node
{
    IP_addres data;
    struct Node *next;

} Node;



Node *HashTable[10];

 //  Function //

void create_hashtable(Node *HashTable[]) //  ‫‪create_hashtable Init‬‬
{
    int index;

   for(index=0;index<10;index++)
    {

        HashTable[index]=NULL;

    }
}



Node* InsertNode(IP_addres Data)  //‫‪hashtable_insert‬‬
{

    Node *first;
    Node *second;
    int index;



        first = (Node *) malloc(sizeof(Node));
        if (first== 0)
        {
            printf ( "out of memory \n");
            return(NULL);
        }

        if (HashTable[index] == NULL)
        {
            HashTable[index]=first;
            first->next=NULL;
            first->data=Data;
        }
        else
        {
            second=HashTable[index];
            first->next=second;
            first->data=Data;
        }

    return first;
}

void hashtable_remove(IP_addres Data)  //hashtable_remove
{
        Node *head;
        Node *first=head;
        Node *second=head;

        if(head==NULL)
            printf("first element is empty\n");

        if(head->data==Data)
        {
            first=head->next;
            free(head);

        }


        while(first->next!=NULL)
     {
         second=first;
         first=first->next;
         if(first->data==Data)
         {
             second->next=first->next;
             free(second);

         }


     }

    }


int hashtable_count(Node *node)
{
    int i=0;
    while(node!=NULL)
    {
        node=node->next;
        i++;
    }
    printf("%d\n",i);

    return i;

}

void menu()
{
    {


        puts("------------------------");
        puts("r. hashtable_remove");
        puts("i. InsertNode");
        puts("c. hashtable_count");
        puts("x. Exit");

    }
}

int main(void) {

    IP_addres IP;
    char c;
    Node *first;
    create_hashtable(HashTable);

    while(1)
    {

    start:        menu();
            printf("Enter IP Address:\n");
                scanf("%x",&IP);
            c = getchar();
            switch(c)
                        {
                        case 'c': /* hashtable_count*/
                            hashtable_count( first);
                            goto start;
                            break;
                        case 'i': /* InsertNode*/
                            InsertNode(IP);
                            goto start;
                            break;
                        case  'r': /* hashtable_remove */
                            hashtable_remove(IP);
                             goto start;
                            break;

                        case  'x': /* Exit */
                        break;

                        }
    }

    return 0;
}

Originally Posted by ilans11il

:86:16: error:
invalid operands to binary == (have ‘IP_addres’ and ‘IP_addres’)

Code:

if(head->data==Data)

Both "head->data" and "Data" are structures and you can't compare them with the "==" operator.
You can only compare its members with each other.

Bye, Andreas

Andreas , Salem

Tank youuuuuuuuuu very much