CODEWITHSUNDEEP
c++functionrandomheader
NrdyBhu1
NrdyBhu1

Reputation: 383

How to call a random function of a class in c++?

I am trying to create a command-line game in C++. I am new to it and just started learning. My game consists of a player class and a dragon class. The classes are declared in separate header files. What I would like to know is, if there is a way to call a random function of a class after declaration.
Like

// ignore the includes
class foo{
    public:
        string name = "foo";
        foo(string name){
            this->name = name;
        }

        void func1(){
            //some code
        }

        void func2(){
            //some code
        }

        void func3(){
            //some code
        }
}


/////
//main.cpp
#include <iostream>
#include "foo.h"

int main(){
    foo bar("hello");
    //call a random function like func1, func2, func3;
    return 0;
}

Upvotes: 1

Views: 274

Answers (2)

Alexander
Alexander

Reputation: 126

I am a beginner myself and I am sure there are much easier/better solutions than mine.

You can try it with cases.

int random_val = rand();
int nr = random_val % 3; 
switch (nr) {
    case 0: bar.func1();
            break;
    case 1: bar.func2();
            break;
    case 2: bar.func3();
            break;
    default:
            std::cout << "Default case" << std::endl;
}

Upvotes: 4

Mestkon
Mestkon

Reputation: 4061

You can make an array with the given functions and generate a random int as an index into the array:

void invoke_random_function(foo& bar)
{
    //make an array of pointers to desired functions
    using func_type = void(foo::*)();
    constexpr func_type funcs[] = {
        &foo::func1,
        &foo::func2,
        &foo::func3
    };
    
    //select a random function from array
    auto random_index = (std::rand() % std::size(funcs)); //use better RNG than std::rand if necessary
    auto random_func = funcs[random_index];

    //invoke the selected function with the given instance of the class         
    (bar.*random_func)(); //funny notation to invoke member function pointers
}

Upvotes: 3

Related Questions