I wrote a LinkedList.h (it should be generic so I use templates). Then now, I try to create an app which takes two data's(maybe string or int, two of them are possible) from user then store them into the LinkedList. Normally I can use this app with store these two data's seperately but the problem comes in when I try to store them with in an object(these two data's inside an object, and one pointer should point one object). I dont sure; can I store data's in objects with using LinkedList structure but I have to implement this app with LinkedList pass with objects. Here my code's. I felt confused...
LinkedList.h (BELOW)
#pragma once
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
using namespace std;
template <class T> class Node {
public:
T data;
Node<T>* next_ptr;
Node() { //Default Constructor
data = ""; //Here I got error, data cant be equal zero //In default, data should be zero and *****
next_ptr = NULL; //next pointer should be NULL
}
Node(T data) { //Default Constructor with parameter
this->data = data; //Given data is Node's data
this->next_ptr = NULL; //Next is NULL
}
};
template <class T> class LinkedList {
Node<T>* head_ptr; //head of linked list
public:
LinkedList() { //Default Constructor
head_ptr = NULL; //In default, head should be NULL
}
void addItem(T&); //For adding item to the list
void showItem(); //For showing items in the list
};
template <class T> void LinkedList<T>::addItem(T& new_data) {
Node<T> *new_node = new Node<T>(); //new node creating
Node<T> *last_ptr = head_ptr; //last is head now, to set node's location
new_node->data = new_data; //new_node's data set to new_data
new_node->next_ptr = NULL; //new_node's next_ptr set to the NULL
if (head_ptr == NULL) { //if head is NULL,
head_ptr = new_node; //new_node should be head
return;
}
while (last_ptr->next_ptr != NULL) { //In this loop, last_ptr
last_ptr = last_ptr->next_ptr; //come to the one node before from
} //end node.
last_ptr->next_ptr = new_node; //last node's next is new node now.
return; //above while loop exist for this.
} //bring last_ptr to one before end node's
template <class T> void LinkedList<T>::showItem() {
Node<T> *show_ptr = head_ptr; //Creating new pointer for the listing
while (show_ptr != NULL) { //Show till pointer be the null
cout << show_ptr->data << endl;
show_ptr = show_ptr->next_ptr; //scroll pointer ******
//In the above line I got error, because the <T> type I think. How can I achieve this?
}
return;
}
Here is the main cpp file.. (BELOW)
#include <iostream>
#include <string>
#include <stdio.h>
#include <windows.h>
#include "LinkedList.h"
#define _CRT_SECURE_NO_WARNINGS
#define clear() printf("\033[H\033[J")
using namespace std;
class lib_instance {
string bookname, username;
public:
lib_instance();
lib_instance(string b, string u) : bookname(b), username(u) {}
lib_instance(string b) : bookname(b) {}
};
class library_apps {
public:
LinkedList<lib_instance> list;
void add_Item() {
string book;
string name;
cout << "Please enter a book name: ";
cin >> book;
cout << "Please enter your name: ";
cin >> name;
lib_instance newItem(book, name);
list.addItem(newItem);
return;
};
void show_Item() {
cout << "\nBooks" << endl;
list.showItem();
cout << endl << "Names" << endl;
list.showItem();
cout << endl;
return;
};
};
int main() {
library_apps apps;
char input;
int a = 0;
cout << "\n\tWelcome to the Library App\n" << endl;
while (a != 5) {
cout << "\n****What do you want to? :\n";
cout << "1.Add a book and name to the library\n";
cout << "5.Show/list books and names in the library\n" << endl;
cin >> input;
if (input != '1') {
if (input != '5') {
cout << "Please enter valid input...\n\n\n";
Sleep(1500); //Sleeps 1.5sec for show the message
clear(); //Clears the screen
main(); //return back to the main
}
}
if (input == '1') { //If input equal with 1, adds items
apps.add_Item();
}
if (input == '5') { //If input equal with 5, shows items
apps.show_Item();
}
Sleep(3000); //Delay
clear(); //Clear the screen and show main menu
}
return 0;
}
lib_instance::lib_instance() {}
In the .h file, I showed which lines has error with an asteriks --> "******" in the end of line. Main idea is, the linkedlist has generic type so I could use every type to create linkedlist. When I sent "object" to the linkedlist, problems are comes in. (I have to use with objects). Probably my way is wrong way but in some way I could do this.
I think that's the structure, and that's the structure I'm trying to implement.
Edit1: And also, I dont know how can I access the data's which are inside object.
Edit2(Error): binary '<<': no operator found which takes a right-hand operand of type 'T' (or there is no acceptable conversion)
error line --> "show_ptr = show_ptr->next_ptr;" end of the .h file