CODEWITHSUNDEEP
c++
msd_2
msd_2

Reputation: 1187

Call functions randomly in a C++ program

I have a C++ program in this fashion

#include<iostream>

string A();
string B();
string C();

int main()
{
  return 0;
}

I want to test an application by using the three functions A(),B() and C() in such a way that I call them randomly from the main() and in this way I test the application. I do not know if there exists any provision or any tweak which will allow me calling the the functions in any order randomly.

Is it possible in C++ to call functions randomly, if yes then what is the best way of doing it ?

Upvotes: 3

Views: 3522

Answers (5)

Mark Ransom
Mark Ransom

Reputation: 308392

If the functions all have the same signature, you can make an array of function pointers.

typedef string (*func_ptr)();

func_ptr funcs[3] = { A, B, C };

cout << funcs[rand() % 3]() << endl;

Upvotes: 5

Frank Osterfeld
Frank Osterfeld

Reputation: 25165

Using C++11:

std::vector<std::function<std::string()>> functions = {a, b, c};
std::cout << functions[rand() % functions.size()]() << std::endl;

Upvotes: 2

fvdalcin
fvdalcin

Reputation: 1047

If your functions have the same signature:

Declare an array of functions

returnType (*p[3]) (type1 x, type2 y, ...);

Initialize the seed of the random number generator:

srand (time(NULL));

Call the functions as many times as you want in a loop:

for(i=0; i < MAX_TIME; i++)    
    p(rand() % 2);

Upvotes: 2

xorguy
xorguy

Reputation: 2744

Put all the functions in a function array:

string(*functions[3])() = { A, B, C };

and then call one randomly by its index:

int main()
{
    (*functions[rand() % 3])();
}

Upvotes: 3

pippin1289
pippin1289

Reputation: 4939

How about a for loop selecting a random number to control which test is called.

for(size_t i = 0; i<NUM_Of_TESTS; ++i) {
  switch(rand() % 3) {
    case 0: A(); break;
    case 1: B(); break;
    case 2: C(); break;
  }
}

A switch statement like this would allow for varying function signatures.

Upvotes: 10

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