c++ - Linked List Problems -

so created class linked_list struct node seems there errors don't know how fix , here code :

#include <iostream> using namespace std;    struct node{  int info;  node *link;  };   class linked_list{   private :  int count; node *first; node *last; node *current;  public:   linked_list() {  count=0; first=null; last=null; }    void initialize_list(){  cout<<"enter number of nodes"<<endl; cin>>count;  first=last=current=new node;  for(int =0;i<count;i++){ cin>>current->info; last->link=current; last=current;    current=new node;} last->link=null; }   bool is_empty(){ if(first==null) { cout<<"the list empty"<<endl; return true; }  else{ cout<<"the list not empty"<<endl; return false;} }   bool search(int x){  for(current=first;current!=null;current=current->link){      if (current->info==x)         return true;     else return false;} }    void insert_first(int x){  count++;  current=new node; current->info=x; current->link=first;  first=current;   if(last==null){ last=current; last->link=null;}}  void insert_last(int x){ count++; current=new node; current->info=x;  last->link=current;  last=current; last->link=null;  if(first==null)  first=current; }   void delete_first(){  if(!is_empty()) { node *p;  p=first; first=first->link; delete p; count --; if(count==0) first=last=null;} }   void delete_last(){  node *p; if(count<=1){ count=0; p=last; delete p; last=first=null;}  else {     p=first; for(p=first;p->link!=last;p=p->link){ last=p; p=p->link; delete p; last->link=null; count--;}} }  };  void main (){    //nothing done here yet    } 

the compiler gave me these errors (it gave me errors on delete_first function):

1-'null' : undeclared identifier

2- '=' : cannot convert 'int' 'struct node *'

both errors on (first=last=null;}) line

your appreciated

first=last=null; error because null should null (all-caps). no need declare/define null, it's in implementations header files (in case, <iostream>).

actually, you'll find null macro expands 0 (or (void*)0). ie #define null (void*)0.

let me know if fixes both errors.