C++ composition circular dependency - c++

I'm trying to learn C++ and currently I'm trying to know how to implement an object composition in this language.
I have a Character class which is inherited by a Hero and a Monster class.
A Character has a NormalAbility and a SpecialAbility.
I've made the NormalAbility and SpecialAbility classes and both are inheriting an Ability superclass.
My problem is that when I put the #include "Character.h" in Ability.h the normalAbility and specialAbility variables in Character.h don't get recognized as their respected classes. Errors such as "syntax error : identifier string" shows in the headers of both Ability inherited classes
Here's my code:
Character.h
#pragma once
#include <string>
#include "NormalAbility.h"
#include "SpecialAbility.h"
using namespace std;
class Character
{
public:
Character(string name, string type, int hp, NormalAbility na,
SpecialAbility sa);
bool isDead();
void damage(int amt);
void heal(int amt);
void attack(Character* c, int amt);
private:
string name;
string type;
int hp;
int maxHp;
NormalAbility* normalAblity;
SpecialAbility* specialAbility;
}
Character.cpp
#include "Character.h"
#include <iostream>
Character::Character(string name, string type, int hp, NormalAbility* na,
SpecialAbility* sa)
{
this->name = name;
this->type = type;
this->maxHp = hp;
this->hp = hp;
normalAbility = na;
specialAbility = sa;
}
bool Character::isDead(){
return hp <= 0;
}
void Character::damage(int amt){
if (hp > 0){
hp -= amt;
}
else{
hp = 0;
}
}
void Character::heal(int amt){
if (hp + amt > maxHp){
hp = maxHp;
}
else{
hp += amt;
}
}
void Character::attack(Character* c, int amt){
c->damage(amt);
}
Hero.h
#pragma once
#include "Character.h"
#include <string>
using namespace std;
class Hero :
public Character
{
public:
Hero(string name, int hp);
}
Hero.cpp
#include "Hero.h"
#include <iostream>
Hero::Hero(string name, int hp)
: Character(name, "Hero", hp)
{
}
Ability.h
#pragma once
#include <string>
#include "Character.h"
using namespace std;
class Ability
{
public:
Ability(string name, string type, Character* owner);
void levelUp();
private:
string name;
string type;
int level;
Character* owner;
}
Ability.cpp
#include "Ability.h"
Ability::Ability(string name, string type, Character* owner)
{
this->name = name;
this->type = type;
this->owner = owner;
level = 1;
}
void Ability::levelUp(){
level++;
}
NormalAbility.h
#pragma once
#include "Ability.h"
#include <string>
using namespace std;
class NormalAbility :
public Ability
{
public:
NormalAbility(string name);
}
NormalAbility.cpp
#pragma once
#include "NormalAbility.h"
#include <string>
using namespace std;
NormalAbility::NormalAbility(string name) : Ability(name, "Normal")
{
//some codes
}

This way you avoid the circular include of the .h files, because you're including it in the .cpp, and in the .h you're saying that, "Character exists but don't care about his definition right now"
Ability.h
#pragma once
#include <string>
class Character;
using namespace std;
class Ability
{
public:
Ability(string name, string type, Character* owner);
void levelUp();
private:
string name;
string type;
int level;
Character* owner;
}
Ability.cpp
#include "Ability.h"
#include "Character.h"
Ability::Ability(string name, string type, Character* owner)
{
this->name = name;
this->type = type;
this->owner = owner;
level = 1;
}
void Ability::levelUp(){
level++;
}

Related

Why is the Default Parameter being used each time? Initializing classes

When I printed the variables passed through, the default is printed first, followed by what I want passed. So the final result remains the same. The initialization is found in Owner.h and Owner.cpp. Variables are passed starting from the Dog.cpp. I've also tried changing my print statements to Dog.owner... but the result was the same.
Owner.h
#define OWNER_H
#include <iostream>
#include <string>
#include "Dog.h"
using namespace std;
class Owner {
private:
string name;
int age;
public:
Owner(string ownerName = "Lucy" , int ownerAge = 10); // default params
string getName();
int getAge();
};
#endif
Owner.cpp
#include <iostream>
#include <string>
#include "Dog.h"
using namespace std;
// Getters
string Owner::getName() {return name;}
int Owner::getAge() {return age;}
// Constructors
Owner::Owner(string ownerName, int ownerAge) :name(ownerName), age(ownerAge) {
Owner::getName();
Owner::getAge();
}
Dog.h
#ifndef DOG_H
#define DOG_H
#include <iostream>
#include <string>
#include "Owner.h"
using namespace std;
class Dog {
private:
string breed;
int age;
Owner owner;
static int dogCount;
public:
Dog();
Dog(string, int);
// Getter and Setter methods
void setBreed(string var);
void setAge(int var);
string getBreed();
int getAge();
// Other
void printDogInfo();
static int getDogCount() {return dogCount;}
};
#endif
Dog.cpp
#include <iostream>
#include <string>
#include "Dog.h"
#include "Owner.h"
using namespace std;
// Constructors
Dog::Dog(string ownerName, int ownerAge) {
Owner(ownerName, ownerAge);
dogCount++;
}
Dog::Dog() {
}
void Dog::printDogInfo() {
cout << "owner: " << owner.getName() << ", " << owner.getAge() << " yo" << endl << endl;
}
int main() {
Dog myDog1("Belle", 15);
myDog1.setBreed("Siberian Husky");
myDog1.setAge(2);
myDog1.printDogInfo();
return 0;
}
Dog::Dog(string ownerName, int ownerAge) {
Owner(ownerName, ownerAge);
dogCount++;
}
By:
Dog::Dog(string ownerName, int ownerAge) : Owner(ownerName, ownerAge) {
dogCount++;
}
Probably, you also want to fix this:
Owner::Owner(string ownerName, int ownerAge) :name(ownerName), age(ownerAge) {
// Owner::getName(); not needed
// Owner::getAge(); not needed
}
Dog::Dog(string ownerName, int ownerAge) {
Owner(ownerName, ownerAge);
dogCount++;
}
is equivalent to
Dog::Dog(string ownerName, int ownerAge) :
breed(),
owner()
{
Owner(ownerName, ownerAge); // Create temporary
dogCount++;
}
You probably want instead:
Dog::Dog(string ownerName, int ownerAge) :
breed(),
age(0),
owner(ownerName, ownerAge)
{
dogCount++;
}

No variable member function declared in class?

can sombody explain to me why my code will not work, and how to fix it thanks :)
I keep recieving this error :
no 'int burrito::setName()' member function declared in class 'burrito'
My goal is to call a function from a different class file
My main.cpp :
#include <iostream>
#include "burrito.h"
using namespace std;
int main()
{
burrito a;
a.setName("Ammar T.");
return 0;
}
My class header (burrito.h)
#ifndef BURRITO_H
#define BURRITO_H
class burrito
{
public:
burrito();
};
#endif // BURRITO_H
My class file (burrito.cpp):
#include "burrito.h"
#include <iostream>
using namespace std;
burrito::setName()
{
public:
void setName(string x){
name = x;
};
burrito::getName(){
string getName(){
return name;
};
}
burrito::variables(string name){
string name;
};
private:
string name;
};
Your code is a mess. You need to write function prototypes in the header file and function definitions in the cpp file. You are missing some basic coding structures. See below and learn this pattern of coding:
This code should work and enjoy burritos !
main():
#include <iostream>
#include "Header.h"
int main()
{
burrito a;
a.setName("Ammar T.");
std::cout << a.getName() << "\n";
getchar();
return 0;
}
CPP file:
#include "Header.h"
#include <string>
void burrito::setName(std::string x) { this->name = x; }
std::string burrito::getName() { return this->name; }
Header file:
#include <string>
class burrito
{
private:
std::string name;
public:
void setName(std::string);
std::string getName();
//variables(string name) {string name;} // What do you mean by this??
};
Your poor little burrito is confused. Confused burritos can't help much.
You may want your burrito declaration as:
class Burrito
{
public:
Burrito();
void set_name(const std::string& new_name);
std::string get_name() const;
private:
std::string name;
};
The methods could be defined in the source file as:
void
Burrito::set_name(const std::string& new_name)
{
name = new_name;
}
std::string
Burrito::get_name() const
{
return name;
}
The header file only has a constructor for the class. The member functions
setName(string) and getName()
are not declared in the header file and that is why you get the error.
Also, you need to specify the return type for functions.
One way to do this would be
//Header
//burrito.h
class burrito{
private:
string burrito_name;
public:
burrito();
string getName();
void setName(string);
}
//burrito.cpp
#include "burrito.h"
#include <iostream>
using namespace std;
string burrito::getName()
{
return burrito_name;
}
void burrito::setName(string bname)
{
bname =burrito_name;
}
This is a simple example for class in C++,
Save this in burrito.cpp file then compile and run it:
#include <iostream>
#include <string>
using namespace std;
class burrito {
public:
void setName(string s);
string getName();
private:
string name;
};
void burrito::setName(string s) {
name = s;
}
string burrito::getName() {
return name;
}
int main() {
burrito a;
a.setName("Ammar T.");
std::cout << a.getName() << "\n";
return 0;
}

error: No matching function for call to class object

Each time I've attempted to build my project, I receive the same error:
>error: no matching function for call to 'Agent::Agent()'
>note: candidates are: Agent::Agent(std::string, room*)
>note: Agent::Agent(const Agent&)
Initially I assumed that I was feeding the wrong values, but even after seemingly correcting, I still get the same error.
main
#include <iostream>
#include <string>
#include <sstream>
#include "room.h"
#include "Thing.h"
//#include "Agent.h"
//#include "Grue.h"
//#include "Player.h"
using namespace std;
int main()
{
srand(time(NULL));
room *entrance = new room("Entrance","A wide open entrance...", 100);
room *hallway = new room("Hallway","A long hallway...", 50);
room *ballroom = new room("Ballroom","A huge ballroom...", 200);
room *garden = new room("Garden","A lush garden...", 150);
entrance->link("south", hallway);
hallway->link("north", entrance);
hallway->link("east", ballroom);
ballroom->link("west", hallway);
ballroom->link("east", garden);
hallway->printLinked();
while(true)
{
for(int i = 0; i < agents.size(); i++)
{
bool ok = agents[i]->act();
if(!ok)
{
cout << "Game quits." << endl;
return 0;
}
}
}
Player *josh = new Player("Josh", entrance);
Player *tracy = new Player("Tracy", entrance);
game.addAgent(josh);
game.addAgent(tracy);
cout << "Welcome!" << endl;
// the step() function in the Game class will eventually
// return false, when a player chooses to quit;
// this tiny "while" loop keeps asking the game.step()
// function if it is false or true; the effect is
// that the step() function is called repeatedly
// until it returns false
while(game.step());
return 0;
}
Thing header
#ifndef THING_H
#define THING_H
#include <iostream>
#include <string>
#include "room.h"
class room;
class Thing
{
private:
std::string name, desc;
protected:
room* cur_room;
public:
Thing(std::string _name, std::string _desc);
std::string getName();
std::string getDesc();
int getSize();
};
#endif // THING_H
Thing cpp
#include "Thing.h"
Thing::Thing(std::string _name, std::string _desc)
{
name = _name;
desc = _desc;
cur_room = NULL;
}
std::string Thing::getName()
{
return name;
}
std::string Thing::getDesc()
{
return desc;
}
int Thing::getSize()
{
return size;
}
Agent header
#ifndef AGENT_H
#define AGENT_H
#include "Thing.h"
#include <iostream>
#include <string>
#include "room.h"
class Agent : public Thing
{
protected:
//bool walk(std::string exit);
room *cur_room;
std::string name;
public:
Agent(std::string _name, room *_cur_room);
void get_curroom();
virtual bool act() = 0;
std::string getName() { return name; }
};
#endif // AGENT_H
Agent cpp
#include "Agent.h"
Agent::Agent(std::string _name, room *_cur_room)
{
name = _name;
room = _cur_room;
}
bool Agent::walk(std::string exit)
{
return 0;
}
bool Agent::act()
{
return 0;
}
void Agent::get_curroom()
{
return cur_room;
}
Player header
#ifndef PLAYER_H
#define PLAYER_H
#include <iostream>
#include <string>
#include "Agent.h"
#include "room.h"
class room;
class Player : public Agent
{
private:
std::string name;
protected:
public:
Player(std::string _name, room *starting_room);
bool Act();
};
#endif // PLAYER_H
Player cpp
#include "Player.h"
Player::Player(std::string _name, room *starting_room)
{
name = _name;
cur_room = starting_room;
}
bool Player::Act()
{
std::cout << "Where do you want to go? (or 'quit')" << std::endl;
}
I'm honestly stumped on where to go next. Any help is greatly appreciated!
In your inheritance chain of Player<-Agent<-Thing, you aren't passing the constructor parameters up to the parent. So, you need to change the Player constructor to:
Player::Player(std::string _name, room *starting_room)
:Agent(_name, starting_room)
{
name = _name;
cur_room = starting_room;
}
And you need to change the Agent constructor to:
Agent::Agent(std::string _name, room *_cur_room)
:Thing(_name, "")
{
name = _name;
room = _cur_room;
}
The parts I added after the colons are called initialization lists. One use of these is to call the constructor of the parent class. In C++, you have to call the parent class's constructor by name, since there is no keyword to reference the parent class generally.
The problem is that in the constructor of Player you don't call the constructor of the base class Agent and the latter doesn't have the default constructor. To fix it call the Agent's constructor (or add the default constructor):
Player::Player(std::string _name, room *starting_room)
: Agent(_name, starting_room)
{
// ...
}

C++ - Declaration of method incompatible

EDIT:
I'm using namespace std
I'm using VS10
Room is a separate class
I've included the memory header in all necessary files
The original error was an Intellisense error I was getting before building. After building, I got a buttload more:
[The original Intellisense error before building] declaration is incompatible with "std::tr1::shared_ptr<< error-type >> Option::getRoom()
'std::tr1::shared_ptr<_Ty> Option::getRoom(void)' : overloaded function differs only by return type from 'std::tr1::shared_ptr Option::getRoom(void)'
'Option::getRoom' : redefinition; different basic types
'Option::getRoom' uses undefined class 'std::tr1::shared_ptr'
These are related to this piece of code in Option.cpp:
shared_ptr<Room> Option::getRoom(){
shared_ptr<Room> room(new Room);
return room;
}
The corresponding code in Option.hpp:
public:
virtual shared_ptr<Room> getRoom();
Error 'RoomOption::getRoom': overriding virtual function return type differs and is not covariant from 'Option::getRoom'
[IntelliSense] return type is not identical to nor covariant with return type "std::tr1::shared_ptr<< error-type >>" of overridden virtual function function "Option::getRoom"
This is related to this piece of code in RoomOption.hpp, a subclass of Option:
public:
shared_ptr<Room> getRoom();
Here's all the code from the two classes I'm having trouble with:
Option.h:
#pragma once
#include "Room.h"
#include <memory>
using namespace std;
class Option
{
protected:
int id;
char* text;
public:
Option(void);
Option(int, char*);
virtual ~Option(void);
char* getText();
int getID();
virtual shared_ptr<Room> getRoom();
};
Option.cpp:
#include "Option.h"
#include "Room.h"
#include <memory>
using namespace std;
Option::Option(void)
{
}
Option::Option(int newID, char* newText){
id = newID;
text = newText;
}
Option::~Option(void)
{
}
char* Option::getText(){
return text;
}
int Option::getID(){
return id;
}
shared_ptr<Room> Option::getRoom(){
shared_ptr<Room> room(new Room());
return room;
//note that this function will never be used. I'd prefer to
//pass back a null pointer but I couldn't do that either.
}
RoomOption.h:
#pragma once
#include "Option.h"
#include "Room.h"
#include <memory>
using namespace std;
class RoomOption :
public Option
{
private:
shared_ptr<Room> room;
public:
RoomOption(void);
RoomOption(int, char*, shared_ptr<Room>);
~RoomOption(void);
void setRoom(shared_ptr<Room>);
shared_ptr<Room> getRoom();
};
RoomOption.cpp:
#include "RoomOption.h"
#include "Room.h"
#include <memory>
using namespace std;
RoomOption::RoomOption(void)
{
}
RoomOption::RoomOption(int newID, char* newText, shared_ptr<Room> newRoom)
{
id = newID;
strcpy(text, newText);
room = newRoom;
}
RoomOption::~RoomOption(void)
{
}
void RoomOption::setRoom(shared_ptr<Room> newRoom){
room = newRoom;
}
shared_ptr<Room> RoomOption::getRoom(){
return room;
}
This code compiles without error at /W4 /WX with VS 2010:
#include <memory>
struct Room {};
class Option {
public:
std::shared_ptr<Room> getRoom();
};
std::shared_ptr<Room> Option::getRoom(){
std::shared_ptr<Room> room(new Room());
return room;
}
int main() {
Option opt;
std::shared_ptr<Room> room = opt.getRoom();
return 0;
}
What are you doing differently?
Is Room declared at the point where it's used in the getRoom() call in Option.hpp?
Have you tried removing the () from new Room() in case you're somehow getting hit by the most vexing parse, possibly in other code we can't see??

an error "has no member named"

I have this snippet of the code
account.cpp
#include "account.h"
#include <iostream>
#include <string>
using namespace std;
Account::Account(string firstName, string lastName, int id)
: strFirstName(firstName), strLastName(lastName), nID(id) {}
void Account::printAccount(){
cout << strFirstName;
}
account.h
#include <string>
using std::string;
class Account{
private:
string strLastName; //Client's last name
string strFirstName; //Client's first name
int nID; //Client's ID number
int nLines; //Number of lines related to account
double lastBill;
public:
Account(string firstName, string lastName, int id);
void printAccount();
};
company.h
#ifndef CELLULAR_COMPANY_H
#define CELLULAR_COMPANY_H
#include <string>
#include <list>
#include <iostream>
#include "account.h"
using namespace std;
class Company {
private:
list<Account> listOfAccounts;
public:
void addAccount(string firstName, string lastName, int id) {
Account newAccount(firstName, lastName, id);
listOfAccounts.push_back(newAccount);
}
void printAccounts(){
for(list<Account>::iterator i = listOfAccounts.begin(); i != listOfAccounts.end(); ++i){
i.printAccount; //here bug
}
}
};
#endif // CELLULAR_COMPANY_H
main.cpp
#include "cellularcompany.h"
int main(){
Company newCompany;
newCompany.addAccount("Pavel", "Nedved", 11111);
newCompany.printAccounts();
return 0;
}
can somebody please explain what does my error mean? thanks in advance (I have it in company.h see comment there)
I have bug 'struct std::_List_iterator<Account>' has no member named 'printAccount'
You forgot the parentheses after printAccount(). Otherwise, it's not a method call. Also, you need to use the -> operator, since it's an iterator.
for(list<Account>::iterator i = listOfAccounts.begin();
i != listOfAccounts.end(); ++i)
{
i->printAccount(); // Note the ()!
// This is equivalent to (*i).printAccount();
}
Try to change i.printAccount; to i->printAccount();