New to C++ Classes

This is a discussion on New to C++ Classes within the C++ Programming forums, part of the General Programming Boards category; What is restart? I assume it is a single character. If that's the case, then you need to use single ...

  1. #46
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    What is restart? I assume it is a single character. If that's the case, then you need to use single quotes around 'y' and 'Y' to indicate that they are characters as well. The double quotes mean they are strings.

  2. #47
    Frequently Quite Prolix dwks's Avatar
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    Also, you could use tolower() from <cctype>, which would allow you to use only one comparison.
    Code:
    if(tolower(restart) = 'y')
    tolower() converts the character passed to it to lowercase. If it's already lowercase or not a letter, it just returns the character it was passed.

    [edit] I mean ==. Whoops. [/edit]
    Last edited by dwks; 06-21-2007 at 02:02 PM.
    dwk

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  3. #48
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    Psst...
    Code:
    if(tolower(restart) == 'y')

  4. #49
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    Can I use the tolower for strings also?

  5. #50
    C++ Witch laserlight's Avatar
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    No, but you can use it on each character in a string.
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  6. #51
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    OK, compiled and ran. The only thing is, all of the things (money, lives, attack points, and defense points) are way way way higher than they are supposed to be.

    I put the Manager function above the other functions in GameManager.cpp and I am now getting these errors:
    GameManager.h:13: error: ISO C++ forbids initialization of member `money'
    GameManager.h:13: error: making `money' static
    GameManager.h:13: error: ISO C++ forbids in-class initialization of non-const static member `money'

    for each variable when I print out all the variables when showing the the player stats.

  7. #52
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    Do you have a separate class instance for each player, or do you keep all the data in one GameManager?

    Why is money static?

  8. #53
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    There is only one player, the person playing.
    I didn't make money static. The integer money is private though. I have it here:
    Code:
    class GameManager
    {
    private:
           int money = 200;
           int lives = 3;
           int attack = 0;
           int defense = 0;
           string battle;
           string shop;
           char restart;
           string ShopBattle;
    That's the GameManager.h file.


    I don't know if I should give the variables values here or in the Manager() function.

  9. #54
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    You need to initialize the variables in the constructor (which is probably what you meant by "the Manager() function").
    Last edited by Daved; 06-21-2007 at 03:25 PM.

  10. #55
    Frequently Quite Prolix dwks's Avatar
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    You can initialize class variables in a constructor with the ordinary assignment operator:
    Code:
    class c {
    public:
        int value;
        c(int x);
    };
    
    c::c(int x) {
        value = x;
    }
    Or you can use an initializer list (which you have to use if the variables are constant):
    Code:
    class c {
    public:
        int value;
        c(int x) : value(x);
    };
    
    c::c(int x) {
    
    }
    For multiple variables, the initializer list looks like this:
    Code:
    constuctor() : one(x), two(y), name(firstname) ...;
    The variables should appear in the order they are declared in the class.

    Also, the constructor can be declared inside the class, making it inline. But that doesn't matter if there's nothing in the body of the constructor.
    Code:
    class constructor {
        constructor() : one(x), two(y) {}
    };
    dwk

    Seek and ye shall find. quaere et invenies.

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  11. #56
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    OK, it's compiling fine now, thanks for all the help.
    However, the:
    Code:
    int GameManager::GetMoney()
    {
        return money;
    }
    functions aren't working (I have one for each variable). Either that isn't working or the:
    Code:
    void GameManager::AddAttack(int amount)
    {
         attack =+ amount;
    }
    functions aren't working.
    Maybe both. I know this because when I played the game I beat every single robot even though I shouldn't and when I should have won money the amount in the stats stayed the same. If you need me to post the code I will.

  12. #57
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    >> If you need me to post the code I will.
    Maybe that would be best.

    >> attack =+ amount;
    Make sure you copy and paste to prevent typos.

  13. #58
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    GameManager.cpp
    Code:
    #include "ShopClass.h"
    #include "BattleClass.h"
    #include "GameManager.h"
    #include <iostream>
    #include <cctype>
    using namespace std;
    
    void GameManager::Manager()
    {
         int money = 200;
         int lives = 3;
         int attack = 0;
         int defense = 0;
         ShopClass shop;
         BattleClass battle;
         cout << "Current Status:\n";
         cout << "Money: $" << money << "\n";
         cout << "Lives: " << lives << "\n";
         cout << "Attack Points: " << attack << "\n";
         cout << "Defense Points: " << defense << "\n";
         cout << "Would you like to visit the shop or battle robots?\n(Please enter either Shop or Battle)\n";
         cin >> ShopBattle;
         
         if (ShopBattle == "Shop" || ShopBattle == "shop") {
                        shop.Shop();
         } else if (ShopBattle == "Battle" || ShopBattle == "battle") {
                battle.Battle();
         } else {
                cout << "Error: Invalid Input";
         }
    }
    
    int GameManager::GetMoney()
    {
        return money;
    }
    int GameManager::GetAttack()
    {
        return attack;
    }
    int GameManager::GetDefense()
    {
        return defense;
    }
    int GameManager::GetLives()
    {
        return lives;
    }
    
    void GameManager::AddMoney(int amount)
    {
         money =+ amount;
         if (money < 0)
              money = 0;
    }
    
    void GameManager::Lives()
    {
         GameManager manager;
         lives =- 1;
         if (lives == 0)
            cout << "Game Over\n";
            cout << "Would you like to start again? (y or n)";
            cin >> restart;
            if (tolower(restart) == 'y') {
               money = 200;
               lives = 3;
               attack = 0;
               defense = 0;
               manager.Manager();
            } else if (tolower(restart) == 'n') {
                   
            } else {
                   cout << "Error: Invalid Input\n";
                   manager.Lives();
            }
    }
    
    void GameManager::AddAttack(int amount)
    {
         attack =+ amount;
    }
    
    void GameManager::AddDefense(int amount)
    {
         defense =+ amount;
    }
    ..and an example of code that needs to use some of the variables
    Code:
     if (manager.GetAttack() >= 1){
               cout << "Attack Successful\nYou Won $200\n\n";
               manager.AddMoney(200);           
            } else {
              cout << "You Lost\n\n";
              manager.Lives();
            }

  14. #59
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    >> attack =+ amount;
    That compiles?

  15. #60
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    Yeah, should I make it:
    attack = attack + amount?

    I probably picked that up from Java :x

    Still wont work.
    Last edited by Cypher; 06-21-2007 at 08:05 PM.

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