• 0

C++ linked list and objects


Question

I have been given an assignment from my uni to create a bank where im to have customers with multiple accounts and different account types, also then add other things like loans etc.

Im having problems getting a linked list to work with the class objects. my aim is to store all the customers details, and account details in the class objects then list all the customers in the linked list instead of using something like an array as we get more marks for using linked lists.

so far i have managed to get it so the customer can be created and pointing to just one account. but i am stuggling with understanding how im to then create the linked list so it connects to the class object.

these are some bits of the code which i have so far:

AssignmentBank.cpp (main)

	Account tempAccount(001, 500, 600, "Current");
	Customer tempCustomer("Fred", 01, 0.5, 'M',"180690", &tempAccount);
	CustomerList CL;	
	CL.addCustomer(&tempCustomer);

with this im not sure if im doing it the correct way, but am i to create the objects then pass in the refference to it, which is then stored in the linked list?

CustomerList.cpp

#include "CustomerList.h"
#include <iostream>

using namespace std ;

CustomerList::CustomerList()
{
    front = back = 0;
}

bool CustomerList::isEmpty()
{
   return front == 0;
}


void CustomerList::addCustomer(Customer *tempCustomer)
{
	Node* insert  = new Node(tempCustomer); 
	if (front == 0)
   {
      back = front = insert;
   }
   else
   {
      back-> next = insert ;      
	   back = back -> next ;
   }
}

CustomerList::removeCustomer()
{
   Customer tempCustomer; Node* temp;

	if (front != 0)
   {
      tempCustomer = front -> customerRef;
      temp = front;
      front = front -> next ;
      delete temp ;
      if (front == 0) back = 0;
      return tempCustomer;
   }
   else return '\0';

}


CustomerList::~CustomerList()
{
   Node * temp;
	while(front != 0)
	{
		temp = front;
		front = front -> next;
		delete temp;  
	}
}


void CustomerList::print()
{
	Node * temp = front;
   if (temp != 0 ) 
   {
	   while (temp != 0)
	   {
		   cout << temp -> customerRef.getName() ;
		   temp = temp -> next;
      }
   }
   else cout << "empty";
   cout << endl;

}

CustomerList.h

#include "Customer.h"

class Node
{
public:
	Node* next;
	Customer customerRef;
	Node(tempCustomer)
	{
		Customer *tempCustomer;
		next = 0;
	}	
};


class CustomerList
{
	Node* front;
        Node* back;
public:
	CustomerList();
	~CustomerList();
	void addCustomer(Customer *tempCustomer);
   removeCustomer( );
	bool isEmpty();
   void print() ;

};

any help at all would be useful.

I have gone to extra classes at uni and asked lecturers over and over but they dont seem to be helping me much.

Link to comment
https://www.neowin.net/forum/topic/955220-c-linked-list-and-objects/
Share on other sites

7 answers to this question

Recommended Posts

  • 0

The problem is your Node class: you have to decide whether you want it to hold copies of Customers or references(pointers) to Customers. Both approaches are valid yet different. If you go with references, you have to ensure that the original Customers remain alive otherwise the references will soon point to nothing. If you go with values (copies), there's no dangling reference issue but of course you encur the performance cost of the copy.

This is basically how I would code it:

struct Node // if you only want public members, use a struct, it's the same thing as class except everything is public by default
{
        Node* m_next;
        Customer& m_customer;
        Node(Customer& customer) : m_next(0), m_customer(customer) {}   
};

And then the addCustomer method would look virtually identical to yours (except I like references better when I can use them):

void CustomerList::addCustomer(Customer& customer)
{
    Node* insert  = new Node(customer); 
    if (front == 0)
   {
      back = front = insert;
   }
   else
   {
      back->next = insert;   
      back = back ->next;
   }
}

  • 0

A struct is a class in C++. They are literally duplicate keywords. The only difference is that default visibility is private in a class, whereas it is public in a struct. So if all it takes to satisfy your teacher is to not use the keyword "struct", change "struct" by "class" and add "public:" before the member declarations. :laugh:

Seriously though, it's not clear to me what your teacher meant by that. The C++ way of doing a linked list is usually:

#include <list>

int main()
{
    // look ma no code
    std::list<int> linkedList;
    linkedList.push_back(1);
    // etc
}

  • 0

thank you, i got it working after playing around a little with what i already had. can now add customers and display them how i need to.

problem is now i want to be able to have multiple accounts for each customer.

at the moment i have:

customer.cpp

Customer::Customer(string tempName, string tempTelNo, double tempInterestRate, char tempSex, string tempDoB, Account *bankAccount)
{
	name=tempName;
	telNo=tempTelNo;
	interestRate=tempInterestRate;
	sex=tempSex;
	DoB=tempDoB;
	accountRef=bankAccount;
}

and an example of creating a customer is:

AssignmentBank.cpp

CL.addCustomer(new Customer("Fred", "01785211211", 0.5, 'M',"110284", new Account(002, 600, 700, "Current")));

thing is i want to be able to make lots of accounts without a limit really.

and if i go to the array option then i cant change the size of the array can i?

can someone point me in the right direction of how i can do this?

  • 0

You need a linked list structure for everything you need a list of - customers, accounts, etc. Rather than duplicating the linked list code for each type of list, look into templating!

When creating your new example customer, you'd do it something like:

Customer* custTmp = new Customer("Fred", "01785211211", 0.5, 'M', "110284");
CustTmp->addAccount(new Account(002, 600, 700, "Current"));
CustTmp->addAccount(new Account(003, 601, 701, "Current"));
//etc
CL.addCustomer(custTmp);
custTmp = 0; //no need to keep a copy of the pointer here in main(), the linked list has it and can handle freeing up memory when necessary, safer to disarm this!

  • 0
  On 23/11/2010 at 00:18, theblazingangel said:

You need a linked list structure for everything you need a list of - customers, accounts, etc. Rather than duplicating the linked list code for each type of list, look into templating!

When creating your new example customer, you'd do it something like:

Customer* custTmp = new Customer("Fred", "01785211211", 0.5, 'M', "110284");
CustTmp->addAccount(new Account(002, 600, 700, "Current"));
CustTmp->addAccount(new Account(003, 601, 701, "Current"));
//etc
CL.addCustomer(custTmp);
custTmp = 0; //no need to keep a copy of the pointer here in main(), the linked list has it and can handle freeing up memory when necessary, safer to disarm this!

I understand how to create them as you have mentioned, just not to sure how to add the references of the accounts to the customer.

  • 0

I haven't used C++ in quite some time, but when I did, I made an arraylist class. Just a doubly linked list... I found it pretty fun to make, and I put it on Google Code.

You can check out the adding method here, among many others: http://code.google.com/p/arraylist/source/browse/trunk/arraylist.cpp#119

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • Bethesda's Deathloop is free to claim on the Epic Games Store this week by Pulasthi Ariyasinghe The Epic Games Store's Mega Sale promotion is in its final week, and that means mystery giveaways are soon ending too. For the finale, Epic Games has called in something big from Bethesda, with the Arkane-developed time loop adventure Deathloop coming in as the latest freebie for PC gamers. Alongside it, the indie adventure Ogu and the Secret Forest is also free. Developed by Arkane Lyon and published by Bethesda, Deathloop comes in touting an action-packed campaign involving plenty of time travel shenanigans. The game is set on the mysterious island of Blackreef, where two rival assassins, Colt and Julianna, are trapped in a time loop. The player, as Colt, has to figure out how to eliminate eight targets within a single day to escape the loop. Each of the assassinations can be taken care of in many ways, including stealth, traps, accidents, or simply going in guns blazing. Aside from gunplay, the title also makes use of supernatural systems very similar to the studio's Dishonored franchise, letting players teleport, go invisible, use telekinesis, and more. There is a multiplayer twist here too, where players, as Julianna, can invade the campaigns of others to take the role of the rival assassin, flipping the tables on the main character and his plans. As for Ogu and the Secret Forest, this is a 2024-released indie adventure featuring hand-drawn characters and various types of puzzles. The 2D game involves befriending characters across a fantasy land as baby Ogu, with plenty of exploration, puzzle solving, and boss battles available. The Deathloop and Ogu and the Secret Forest giveaways are now live on the Epic Games Store for all PC gamers. The promotion is slated to last until June 12, giving you seven days to claim a copy for your library permanently. While the summer mystery giveaways are ending, regular freebies will continue to arrive from the Epic Games Store. When this one comes to an end on Thursday, the SEGA-published humorous hospital simulation entry Two Point Hospital is incoming as the next giveaway.
    • If graphics is all that matters to you go watch a Pixar movie or something, you sound like an absolute baby right now. The game looks great.
    • For sure!! My take is... If the dev choses to use Apple's payment services, sure, Apple can take a cut. Apple disallowing 3rd party payment processing directly within an app, kind of a gray area, its anti-competitive sure, but I can at least see arguments on both sides. Apple blocking or attempting to take a cut from weblinks is pure evil, there is no possible justification at all. Heck, if we take this to the logical next step, Apple should start demanding a cut of retail transactions if the user used GPS directions on an iPhone to get to the store.
  • Recent Achievements

    • Week One Done
      jbatch earned a badge
      Week One Done
    • First Post
      Yianis earned a badge
      First Post
    • Rookie
      GTRoberts went up a rank
      Rookie
    • First Post
      James courage Tabla earned a badge
      First Post
    • Reacting Well
      James courage Tabla earned a badge
      Reacting Well
  • Popular Contributors

    1. 1
      +primortal
      407
    2. 2
      +FloatingFatMan
      181
    3. 3
      snowy owl
      176
    4. 4
      ATLien_0
      170
    5. 5
      Xenon
      135
  • Tell a friend

    Love Neowin? Tell a friend!