CODEWITHSUNDEEP
c++class
Alexander Wolff
Alexander Wolff

Reputation: 152

Dynamically loading class values in C++

I'm fairly new to C++ and and trying to create an epic RPG. The game has four players, each of which has an instance of class Character containing all info (name, level, hp, etc).

class character
{
public:
    string name = "Nameless";       
    int hp = 10;
    int mp = 5;
}

Somewhere else in the code I create playing characters with instances of this class:

character player1;
character player2;
character player3;
character player4;

During combat I will need to be able to change player values dynamically. I have two specific questions:

Perhaps I should be using something else than classes for this, open to suggestions :)

Cheers!

Upvotes: 1

Views: 167

Answers (2)

user764486
user764486

Reputation: 160

How can I change the HP of a randomly selected character? (string = "1"; player[string].hp = 0;)

To easily select a random player to modify, the easiest approach is to place all players in a container such as a vector. Then you can generate a random index into the vector and modify the player at that position.

How can I dynamically choose the class value to be loaded? (string = "hp"; player1.[string] = 10;)

To dynamically choose which property you wish to modify there are a few approaches. An easy solution is shown below with a mapping from string property names to property values. Another approach is to create an enum class which enumerates the different properties and then use that as a key instead of strings.

#include <iostream>
#include <iterator>
#include <random>
#include <string>
#include <unordered_map>
#include <vector>

class character
{
    public:
        std::string name = "Nameless";
        std::unordered_map<std::string, int> properties{
            { "hp", 10 },
            { "mp", 5 }
        };
};

void print_players(const std::vector<character>& players) {
    for (const auto& player : players) {
        std::cout << player.name;
        for (const auto& property : player.properties) {
            std::cout << ", " << property.first << "=" << property.second;
        }
        std::cout << std::endl;
    }
}

int main() {
    auto players = std::vector<character>{
        character{"Player 1"},
        character{"Player 2"},
        character{"Player 3"},
        character{"Player 4"}
    };

    print_players(players);

    auto rng = std::default_random_engine{std::random_device{}()};

    // Select a random player
    auto random_player_distribution = std::uniform_int_distribution<>{0, players.size() - 1};
    auto& random_player = players[random_player_distribution(rng)];

    // Select a random property
    auto random_property_distribution = std::uniform_int_distribution<>{0, random_player.properties.size() - 1};
    auto random_property_iterator = random_player.properties.begin();
    std::advance(random_property_iterator, random_property_distribution(rng));

    // Modify random property
    random_property_iterator->second = 42;

    print_players(players);
}

Upvotes: 2

Qwertiy
Qwertiy

Reputation: 21400

How can I change the HP of a randomly selected character? (string = "1"; player[string].hp = 0;)

Use an array instead of variables:

character players[4];

You can also add references to players if you need them:

character &player1 = players[0];
character &player2 = players[1];
character &player3 = players[2];
character &player4 = players[3];

How can I dynamically choose the class value to be loaded? (string = "hp"; player1.[string] = 10;)

Initially you can't.

Try using dictionary if you need, or overload [] operator in the class.

Anyway, it doesn't seem like a good idea.

Upvotes: 2

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