Question

i’ve been trying to study for my finals by practicing classes and inheritance, this is what I’ve come up with so far for inheritance and such however I’m unsure how to fix the error occuring below.

#include<iostream>
#include<iomanip>
#include<cmath>
#include<string.h>
using namespace std;


//BASE CLASS DEFINITION

class hero
{     
 protected:
            string name;
            string mainAttr;
            int xp;
            double hp;
            double mana;
            double armour;
            int range;
            double attkDmg;
            bool attkType;
  public:
         void dumpData();
         void getName();
         void getMainAttr();
         void getAttkData();
         void setAttkData(string);
         void setBasics(string, string, double, double, double);
         void levelUp();
};

//CLASS FUNCTIONS

void hero::dumpData()
{
 cout << "Name: " << name << endl;
 cout << "Main Attribute: " << mainAttr << endl;
 cout << "XP: " << xp << endl;
 cout << "HP: " << hp << endl;
 cout << "Mana: " << mana << endl;
 cout << "Armour: " << armour << endl;
 cout << "Attack Range: " << range << endl;
 cout << "Attack Damage: " << attkDmg << endl;
 cout << "Attack Type: " << attkType  << endl << endl;
}

void hero::getName()
{
     cout << "Name: " << name << endl;
}

void hero::getMainAttr()
{
     cout << "Main Attribute: " << mainAttr << endl;
}

void hero::getAttkData()
{
     cout << "Attack Range: " << range << endl;
     cout << "Attack Damage: " << attkDmg << endl;
     cout << "Attack Type: " << attkType  << endl;
}

void hero::setAttkData(string attr)
{
     int choice = 0;

     if (attr == "Strength")
 {
          choice = 1;
 }
 if (attr == "Agility")
 {
          choice = 2;
 }
 if (attr == "Intelligence")
 {
          choice = 3;
 }

 switch (choice)
 {
        case 1:
             range = 128;
             attkDmg = 80.0;
             attkType = 0;
             break;

        case 2:
             range = 350;
             attkDmg = 60.0;
             attkType = 0;
             break;

        case 3:
             range = 600;
             attkDmg = 35.0;
             attkType = 1;
             break;

        default:
                break;
 }
}

void hero::setBasics(string heroName, string attribute, double health, double mp, double armourVal)
{
     name = heroName;
     mainAttr = attribute;
     hp = health;
     mana = mp;
     armour = armourVal;
}

void hero::levelUp()
{
     xp = 0;
     hp = hp + (hp * 0.1);
     mana = mana + (mana * 0.1);
     armour = armour + ((armour*0.1) + 1);
     attkDmg = attkDmg + (attkDmg * 0.05);
}

//INHERITED CLASS DEFINITION

class neutHero : protected hero
{
      protected:
            string drops;
            int xpGain;
      public:
         int giveXP(int);
         void dropItems();
};

//INHERITED CLASS FUNCTIONS

int neutHero::giveXP(int exp)
{
    xp += exp;
}

void neutHero::dropItems()
{
     cout << name << " has dropped the following items: " << endl;
     cout << drops << endl;
}

/*
  END OF OO!
*/

//FUNCTION PROTOTYPES
    void dispMenu();


int main()
{
    int exit=0, choice=0, mainAttrChoice=0, heroCreated=0;
    double health, mp, armourVal;
    string heroName, attribute;

    do
    {
      dispMenu();
      cin >> choice;

      switch (choice)
      {
      case 1:
           system("cls");
           cout << "Please enter your hero name: ";
           cin >> heroName;
           cout << "\nPlease enter your primary attribute\n";
           cout << "1. Strength\n" << "2. Agility\n" << "3. Intelligence\n";
           cin >> mainAttrChoice;
           switch (mainAttrChoice)
           {
              case 1:
                   attribute = "Strength";
                   health = 750;
                   mp = 150;
                   armourVal = 2;
                   break;

              case 2:
                   attribute = "Agility";
                   health = 550;
                   mp = 200;
                   armourVal = 6;
                   break;

              case 3:
                   attribute = "Intelligence";
                   health = 450;
                   mp = 450;
                   armourVal = 1;
                   break;
              default:
                   cout << "Choice invalid, please try again.";
                   exit = 1;
                   break;


       hero player;
       player.setBasics(heroName, attribute, health, mp, armourVal);
       player.setAttkData(attribute);
       heroCreated=1;
       system("cls");
       cout << "Your hero has been created!\n\n";
       player.dumpData();
       system("pause");

       break;

      } 
  case 2:
       system("cls");
       if (heroCreated == 1)
       {
          cout << "Your hero has been detailed below.\n\n";
          **player.dumpData(); //ERROR OCCURS HERE !**
          system("pause");
       }
       else
       {
           cout << 
           "You have not created a hero please exit this prompt "
           "and press 1 on the menu to create a hero.";
       }
       break;

  case 3:
       system("cls");
       cout << "Still Under Development";
       system("pause");
       break;

  case 4:
       system("cls");
       exit = 1;
       break;

  default:
       cout << "Your command has not been recognised, please try again.\n";
       system("pause");
       break;
  }
}
while (exit != 1);

system("pause");
return 0;

}

void dispMenu()
{
     system("cls");
     cout <<
     "1. Create New Hero\n"
     "2. View Current Hero\n"
     "3. Fight Stuff\n"     
     "4. Exit\n\n"     
     "Enter your choice: ";
}    

However upon compilation I get the following errors:

220 `player' undeclared (first use this function) 

Unsure exactly how to fix it as I’ve only recently started using OO approach. The error has a comment next to it above and is in case 2 in the main.

Cheers guys.

Answer 1

There is no player variable in scope of that case you need to define a player variable before the whole switch clause if you want all of the cases to be able to access that information. Also you’ll need to thus check if the variable is NULL or not or if object actually created yet before you call a method since it thus won’t guarantee it’s made necessarily.

By doing this, you bring the variable player into scope so that all cases can see it:

hero player;
switch () {
    case 1:
        player.dostuff();
        break;
    case 2:
        player.domorestuff();
        break;
}

If you do

switch () {
    case 1:
        player.dostuff();
        hero player;
        break;
    case 2:
        player.domorestuff();
        break;
}

Then case 2 doesn’t have hero player in scope (assume cases are like if/else clauses) in your code it’s even more apparent because you have braces around your cases.