Hello all, I have almost completed a program that will take 8 numbers from a user and store it in a linked list. Once that is done It will ask for another entry and determine the location of this new entry and how many items are currently bigger than the new entry. I have (pretty much") 95% of it written out but am having problems with my header file (below). I just have to modify my main.cpp file to complete the program but am having problems in the header where I'm getting errors in the codeLL function. I cannot figure out why it keeps giving off this error. I thought I had written everything correctly. Please let me know if you have any suggestions or if you see something that Im just not seeing

Thanks in advance

--------------------Configuration: Linked List Main - Win32 Debug--------------------
Compiling...
Linked List Main.cpp
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(29) : warning C4183: 'deleteLL': member function definition looks like a ctor, but name does not match enclosing class
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(139) : see reference to class template instantiation 'LinkedList<DataType>' being compiled
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(32) : error C2063: 'copyLL' : not a function
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(139) : see reference to class template instantiation 'LinkedList<DataType>' being compiled
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(32) : error C2040: 'copyLL' : 'class LinkedList<DataType>::Node *(class LinkedList<DataType>::Node *)' differs in levels of indirection from 'int'
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(139) : see reference to class template instantiation 'LinkedList<DataType>' being compiled
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(32) : fatal error C1903: unable to recover from previous error(s); stopping compilation
c:\documents and settings\steve\desktop\project 4 linked list\linkedlist.h(139) : see reference to class template instantiation 'LinkedList<DataType>' being compiled
Error executing cl.exe.

Linked List Main.obj - 3 error(s), 1 warning(s)

#ifndef LINKEDLIST
#define LINKEDLIST
#include<iostream.h>

template<typename DataType>
class LinkedList
{
	private:
		class Node
		{
		public:          // Makes it accessible (public) by class Node
			DataType data;
			Node *next;
		};

		Node *first;
		int mySize;

		LinkedList::deleteLL()
		{
			Node *tempP=first, *disposeP;
			while (tempP!=0)
			{
				disposeP=tempP;
				tempP=tempP->next;
				delete disposeP;
			}
			return;
		}

		Node* LinkedList::copyLL(Node* source)
		{
			if (source==0)
				return 0;
			Node* newH=new Node;
			Node *tempP=newH;
			newH->data=source->data;
			source=source->next;
			while (source!=0)
			{
				tempP->next=newNode;
				tempP->data=source->data
					tempP=tempP->next;
				source=source->next;
			}
			temp->next=0;
			return newH;
		}

		public:
			LinkedList::LinkedList()
			{
				mySize=0;
				first=0;
			}
			LinkedList::~LinkedList()
			{
				deleteLL();
			}

			LinkedList::LinkedList( const LinkedList &source)
			{
				mySize=source.first;
				first=copyLL(source.first);
			}

			LinkedList& LinkedList::operator=(const LinkedList& s)
			{
				if (this!=&s)
				{
					deleteLL();
					mySize=s.mySize;
					first=copyLL(s.first)
				}
				return *this;
			}
				bool LinkedList::empty()
				{
					return (first==0);
				}
				void LinkedList::insert(DataType item, unsigned pos)
				{
					if (pos>mySize+1)
					{
						cout<<"Illegal position to insert:"<<pos<<endl;
						return;
					}
					mySize++
						Node* newNode=newNode;
					newNode->data=item;
					Node* prev=first;
					for (int i=1, i<pos, i++)
						prev=prev->next;
					newNode->next=prev->next;
					prev->next=newNode;
				}
				void LinkedList::delete (dataType item)
				{
					mySize--;
					Node* tempP=first;
					Node* prev=0;
					while (tempP!=0 && tempP->data!=item)
					{
						prev=tempP;
						tempP=tempP->next;
					}
					if (tempP!=0 && tempP->data==item)
					{
						prev->next=tempP->next;
						delete tempP;
					}
						else
							cout<<"Item to delete not found"<<endl;
						return;
				}

				int LinkedList::locate(DataType item)
				{
					int position=0;
					Node* ptr=first;
					while(ptr->data<item &&ptr!=0)
					{
						position++;
						ptr=ptr->next;
					}
					return position
				}

						void LinkedList::traverse()
						{
							Node *temp=first;
							while (tempP!=0)
							{
								Process(tempP->data);
								tempP=tempP->next;
							}
							return;
						}
				};
#endif

--------------------------------------------------------------------------------

Hi I've included a basic main which I am using to test the header file

#include "LinkedList.h"
#include<string>
using namespace std;
main()
{


            
}

Dani AI

Generated

Good catch from — the complaint about deleteLL pointed to a class-definition / signature problem, and several of the other errors are cascading from small syntax/template mistakes. The header mixes in-class definitions with out-of-class qualifiers, uses a reserved word as a method name, and contains a handful of typos (missing semicolons, wrong variable names, wrong assignments). Fix the earliest signature/compiler complaint first; the rest will become obvious afterward.

Two concrete rules to follow when cleaning up the header:

  • If a method is defined inside the class body, do not qualify it with LinkedList::. Example (inside the class body):

    void deleteLL() { /* cleanup */ }
    Node* copyLL(Node* source) { /* copy logic */ }
  • If a method is defined outside the class body (in the header for a template) use the template line and fully-qualified name. When returning a nested dependent type use typename:

    template<typename DataType>
    void LinkedList<DataType>::deleteLL() { /* ... */ }
    
    template<typename DataType>
    typename LinkedList<DataType>::Node*
    LinkedList<DataType>::copyLL(Node* source) { /* ... */ }

Other specific problems to correct (short checklist):

  • Rename the delete method (keyword) to remove or erase.
  • Assign sizes correctly: mySize = source.mySize; not source.first.
  • Allocate nodes properly: Node* newNode = new Node; and set newNode->next = 0 at the end of any chain.
  • Fix loop syntax: for (int i = 1; i < pos; ++i) (use semicolons).
  • Check pointer before dereference: while (ptr != 0 && ptr->data < item) not the other way round.
  • Keep variable names consistent (temp vs tempP) and add missing semicolons after statements.
  • In operator=, guard self-assignment, deleteLL(), copy mySize and first = copyLL(s.first);, and return *this;.

Compile after each small fix — the first error normally produces many follow-ons. For a template class it’s simplest to keep complete definitions in the header (or include a separate implementation header) so the compiler can instantiate everything.

Recommended Answers

All 3 Replies

LinkedList::deleteLL() has no return value. That's why the compiler thinks it looks like constructor.

Also, minor point, the LinkedList:: is not nescessary since you are enclosed in that class.

Hi, I gave deleteLL a return type and tried removing LinkedList from 2 functions but that still did not work. I am still getting the same 3 errors. Im just confused as to why its telling me that copyLL is not a function when deleteLL is almost the same and seems to be working.

LinkedList::deleteLL() has no return value. That's why the compiler thinks it looks like constructor.

Also, minor point, the LinkedList:: is not nescessary since you are enclosed in that class.

You changed it to something like "void deleteLL()" and you still get the complaint that "'deleteLL': member function definition looks like a ctor, but name does not match enclosing class"?

That's weird; maybe because its a template I'm not reading it right.

Another thing to think about is to pass a const ref to DataType when you pass it in for searching or copying. That way if it is of any significant size you won't be making extra work (making temp copies and using the copy constructor) for the compiler.

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