Dynamic menu for inventory

Question

I want to make a dynamic menu in which it detects whether you have one or more durability in your inventory. If you do have one or more, it prints out into the menu. Otherwise, it won't.

Here's the code:

#include <iostream>
#include <vector>
using namespace std;
class A {
protected:
    int durability = 3;
public:
    virtual void attack() { };
    virtual int usage() { return 1; };
    virtual string weaponName() { return "Sword x"; };
};
class B : public A
{

public:
    void attack() { durability--; cout << "B Attack" << endl; cout << durability; };
    string weaponName() { return "Sword B"; };

};
class C : public A
{
public:
    int usage() { return durability; };
    void attack() { durability--; cout << "C Attack" << endl;cout << durability; };
    string weaponName() { return "Sword C"; };
};
class D : public A
{

public:
    void attack() { durability--;  cout << "D Attack" << endl;cout << durability; };
    string weaponName() { return "Sword D"; };
};
int main(void)
{
B * b = new B;
C * c = new C;
D * d = new D;
    int k = 10;
    vector <A*> tableOfAs;
    tableOfAs.push_back(b);
    tableOfAs.push_back(c);
    tableOfAs.push_back(d);
    while (--k>0)
    {
        int i = 0;
        vector <A*> options;
        for (i = 0; i < tableOfAs.size(); i++)
        {
            if (tableOfAs[i]->usage() > 0){
                options.push_back(tableOfAs[i]);
        } else { delete tableOfAs[i]; }
        }
        if (options.size() == 0)
            break;
        cout << "Attack Options:" << endl;
            for (i = 0; i < options.size(); i++)
            cout << i << ". " << options[i]->weaponName().c_str() << endl;
        int choise;
        cin >> choise;
        if (choise<0 || choise > options.size()-1)
            cout << "Wrong option" << endl;
        else
            options[choise]->attack();
    }
    return 1;
}

My problem here is that the durability gets zeroed and gets deleted and then after placing another choice, the console crashes.

Answer 1

Try a different approach Create a parent class weapon that has some pure virtual functions.

• weaponName()

• usage()

• attack()

then create classes that inherit these from the weapon class, and implement accordingly.

Do the checks using the usage method, if the result is > 0 then add it to the table of pointers of class weapon. Then use the weaponName function to print the names during the listing of options, and then upon selection use the attack() method from the object that is in the index of the table. So if stick_sword is in index 1 of the table and you call weaponInv[1].attack() it will call the stick_sword attack.

Here is a simple demonstration of the suggested logic:

Updated:

#include <iostream>
#include <vector>

class A {
public:
    virtual void attack() {};
    virtual int usage() { return 1; };
    virtual std::string weaponName() { return "Sword x"; };
};
class B : public A
{
public:
    void attack() { std::cout << "B Attack" << std::endl; };
    std::string weaponName() { return "Sword B"; };

};
class C : public A
{
private:
    int durability;

public:
    C() :durability(3) {};
    int usage() { return durability; };
    void attack() { durability--; std::cout << "C Attack" << std::endl; };
    std::string weaponName() { return "Sword C"; };
};
class D : public A
{
public:
    void attack() { std::cout << "D Attack" << std::endl; };
    std::string weaponName() { return "Sword D"; };
};
int main(void)
{
    B b;
    C c;
    D d;
    int k = 10;
    std::vector <A*> tableOfAs;
    tableOfAs.push_back(&b);
    tableOfAs.push_back(&c);
    tableOfAs.push_back(&d);
    while(--k>0)
    {
        int i = 0;
        std::vector <A*> options;
        for (i = 0; i < tableOfAs.size(); i++)
        {
            if (tableOfAs[i]->usage() > 0)
                options.push_back(tableOfAs[i]);
        }
        if (options.size() == 0)
            break;
        std::cout << "Attack Options:" << std::endl;
        for (i = 0; i < options.size(); i++)
            std::cout << i << ". " << options[i]->weaponName().c_str() << std::endl;
        int choise;
        std::cin >> choise;
        if (choise<0 || choise > options.size() - 1)
            std::cout << "Wrong option" << std::endl;
        else
            options[choise]->attack();
    }
    return 1;
}

Answer 2

Looking back at this old post. I revised the code from boring32. I made it a lot easier to read for those new to programming.

#include <iostream>
#include <string>
#include <vector>
using namespace std;
class baseClass {
public:
    virtual void attack() {};
    virtual int usage() { return 1; }
    virtual string weaponName() { return "Sword x"; }
};
class Sword : public baseClass
{
private:
    int durability;
    string name;
public:
    /*Sets the name and the durability of the sword*/
    Sword(string nameToSet, int dur) :name(nameToSet),durability(dur) {}
    int usage() { return durability; }
    /*Decreases durability by one and tells the name of the sword used in the attack*/
    void attack() { 
        durability--; 
        cout << name <<" Sword Attack" << endl;
    }
    /*returns weapon name*/
    string weaponName() { return name +" Sword"; }
};
int main()
{
    Sword sworda("One", 1), swordb("Two", 2), swordc("Three", 3);
    int loop = 10;
    int choice;
    /*Add swords into a holding container first*/
    vector <baseClass*> holdingContainer;
    holdingContainer.push_back(&sworda);
    holdingContainer.push_back(&swordb);
    holdingContainer.push_back(&swordc);

    while (--loop>0)
    {
        /*Decide whether swords in the holding container has a durability of one or more
          before adding them into the menu*/
        vector <baseClass*> swordWithDurabilityContainer;
        for (int i = 0; i < holdingContainer.size(); i++)
        {
            if (holdingContainer[i]->usage() > 0) {
                swordWithDurabilityContainer.push_back(holdingContainer[i]);
            }
        }

        /*Check if there's any items in the swordWithDurabilityContainer otherwise break out of the loop*/
        if (swordWithDurabilityContainer.size() == 0) { break; }

        /*Print the items*/
        cout << "Attack Options:" << endl;
        for (int i = 0; i < swordWithDurabilityContainer.size(); i++) {
            cout << i << ". " << swordWithDurabilityContainer[i]->weaponName().c_str() << endl;
        }
        /*Ask for user input*/
        cin >> choice;

        /*Check if the input is valid*/
        if (choice<0 || choice > swordWithDurabilityContainer.size() - 1) {
            cout << "Wrong option" << endl;
        }
        else {
            swordWithDurabilityContainer[choice]->attack();
        }
    }
    /*Notify the user that the loop has ended*/
    cout << "No more items in the list(swordWithDurabilityContainer variable)";
}

Back then when I was reading boring32's answer, I couldn't read it because there are barely any comments and variables named as "a", "b" and Classes named "A", "B" and classes which have no correlation with the code. I came back to fix it. Although I'm not sure why some people make it a habit to leave a semi-working code in forums/threads.

No offense to those who also do this.